Uzbekistan
My suggestion for the third Soviet faction has a focus on early expansion and hybrid technologies.
[tab]Architect
Replaces the Engineer and is exactly the same except that it also works as a base provider, meaning you can place buildings next to it. Cost is 500 credits if you have no Architect, otherwise 2000 credits. Regardless of cost it takes 20 seconds to train an Architect (Engineer takes 12 sec). So claiming Oil Derricks is delayed slightly.
[tab]No MCV
Uzbekistan can't make new Construction Yards, instead they use their Architect in order to expand. The positives with this is that expanding is cheap and can be done early on, however since an Architect is slower and much more vulnerable than a MCV expanding is more susceptible for enemy interruption.
Architects also do not actually produce anything, they only provide placement. So if your Conn Yard is destroyed you can't build structures even if you have several Architects. This is a big weakness for Uzbekistan and does a lot to balance the strength of the Architect unit.
[tab]Helipad
This Soviet faction does not use airplanes, instead they make use of helicopters. This means no Paratroopers and no early Spy Plane. As long as a helipad is built they do however finally get a Spy Plane with the Tech Center (as all Soviet factions do in overhaul).
[tab]Light Hind
Based on the Allied Hind but lighter and more agile. Easier to produce as well. Has 55% of the Hind's HP ("dies" on the third attack from a Rocket Soldier) and is placed in the middle of Hind and Longbow in terms of both movement speed and turn speed. Ascends/descends at the same rate of both Longbow and Chinook (which is twice as fast as the regular Hind). Has 7 cells of line-of-sight, the same as the Chinook (in overhaul, Chinook has further vision in vanilla) meaning it isn't well-suitable for scouting. The cost is that of a Submarine, 950 credits, however its simple design makes it easy to mass-produce so it can be manufactured in just 16 seconds (same time as a Chinook). The Light Hind has the same amount of ammo as the regular Hind (same reload time), however it has just one Chaingun. This means it takes twice as long to deal the same amount of damage as a regular Hind. The extra time makes it easier for Rocket Soldiers to launch their missiles at the helicopter before dying.
I just noticed an issue with the Light Hind, it is currently not as fast to manufacture as I had intended... The problem is that I had changed the production time of the Hind, which got inherited by the Light Hind. I'll fix it in the next version of overhaul (if that ever happens).
[tab]Heavy Hind
Also based on the Allied Hind but with twice as much ammo (double reload time) and six chainguns instead of two. Has 75% of the ascend/descend speed of the regular Hind and 93% of its movement speed, otherwise the same health-wise and turn rate-wise. The large amount of chainguns makes the Heavy Hind able to deal extreme damage in short periods of time, quickly bursting down whatever they point at and is especially suited for buildings and light armor. However due to the way Uzbekistan designed its weaponry it is unable to deliver attacks with less than all six chainguns at the same time. This means it is very easy to overkill targets, wasting ammo. The Heavy Hind will be able to kill 8 Rocket Soldiers that are not standing in the same cell while the regular Hind or Light Hind can both kill 12 such targets due to less wasted ammo.
[tab]Chinook
Uzbekistan has access to aerial transportation however due to the usefulness of being able to transport the Architect (especially with the movement speed and build time buffs Chinook has received) the Chinook is only available after a Tech Center has been built. Allies can still build them as soon as they get a Helipad, as normal.
I forgot to mention the lower production timer in my post about the Chinook on page 2 and have updated it (point six is new).
[tab]No Kennel
This hybrid faction does not make use of Attack Dogs.
[tab]No Tesla Coil, Flame Tower (or Flamethrower infantry)
Instead of using typical Soviet defense structures Uzbekistan has been influenced by the Allied defenses instead. A side-effect from having no Flame Tower means no Flamethrower units as well, they do still have Grenadiers though.
[tab]Heavy Turret
The Uzbekistan defense structure is basically an Allied Turret, just dealing twice as much damage. It is extremely powerful against both vehicles and buildings (easily wins against a vanilla Mammoth Tank, almost wins against an overhaul Mammoth Tank and would win against a Tesla Coil). Actually also able to take out three Rocket Soldiers before they take out the turret, without repairing, and four Rocket Soldiers if repairing (overhaul nerfed Rocket Soldiers). Cost is 800 credits and power need is 60 (normal Turret is 600 credits, 40 power). Has 42% turn rate of the normal Turret so incoming attack angle could make a difference. Requires power to operate and can be powered down, just like regular Turret in overhaul. While the regular Turret only has Barracks as prerequisite you need a Service Depot before Heavy Turret becomes available, it would be way too powerful to have access to it early game since you can use Architect to deploy them into enemy Ore fields, usually killing at least one harvester before the enemy can react.
[tab]No walls
This is because of the changes to how walls work. You can make and place walls instantly and further away from other buildings. They can't be crushed and upon destruction they leave a small ruin preventing further building there for two minutes. So with the Architect you can see how exploitable this would be, simply get one close to the enemy base early game and you could ruin their base just by spamming cheap Barbed Wire all over the place. That's the primary reason why walls can't be buildable for Uzbekistan. It would also be very easy to wall yourself in when taking over Oil Derricks, or block bridges and other narrow passages and thus ruining the early game.
[tab]No Advanced Power Plant
With almost nothing in the defense tab the power needs of Uzbekistan is not large. The biggest drain of power would be if several Heavy Turrets were built. In order to still make them vulnerable against power attacks so the strategy remains in the game Uzbekistan can only build regular Power Plants, which can be destroyed faster meaning the player has less time to react to an attack vs power (initiate repair and send troops). It also provides some balancing against the strength of the Architect; to get 200 power you have to spend 2*300 credits, 2*7.2 sec and 2*6 cells of space, with Advanced Power Plant you just need 1*500 credits, 1*12 sec and 1*9 cells of space. That also helps towards keeping the attack-power-strategy viable versus Uzbekistan because in order to replace lost power plants more time, credits and space is needed.
[tab]Destroyer and Submarine
Allied influences are apparent in naval units as well, Uzbekistan has access to Destroyers for ground and air targets as well as regular Submarines for naval targets and scouting. They can also build naval transports like every other faction.
[tab]Nuclear Submarine
Instead of having access to Chronosphere or Iron Curtain Uzbekistan has spent their time researching ways of making Missile Silo portable. They successfully managed to draft blueprints for a huge submarine complete with everything needed for an atom bomb strike. It takes just as long to build as a regular Missile Silo (1 minute) and isn't cheap at 4000 credits, but they are the only faction able to gain access to two nuclear warheads at the same time. If you have both a Missile Silo and Nuclear Sub the enemy will see two timers but if you only have one the enemy won't be able to tell from the timer alone if you have a Missile Silo somewhere or a hidden Nuclear Submarine somewhere.
The elephant in the room concerning this unit is of course that some maps doesn't have water. But many do and it's very easy for Uzbekistan to run with an Architect to the nearest puddle and make a Sub Pen really quickly (which can then be sold after the sub is built to better hide your nuke if you want to). Also, currently maps are designed with water not taken into consideration as much, if a faction was added to the game that actually has a big usage of water of course new maps would be designed around that fact and old popular maps would probably be modified to add at least some water somewhere. Even without the Nuclear Sub the faction still has a lot to offer on land-only maps, this unit is very end-game and very much something that victory doesn't depend upon. With all this in mind I don't see water requirement for one of its high-tech units as a deal-breaker for this faction.
[tab]Spotter
An iconic unit for Uzbekistan serving several roles. It is fast, can take out infantry, provides good vision, detects cloaked units and works as the team's primary anti-air defense. All this at an affordable price of 550 credits. Order the Spotter to deploy to make its driver exit the vehicle and set up an outpost. While in the outpost the unit will have the same line-of-sight as Hind/Yak (10 cells). The driver will then however only have his M1 Carbine since the M60 Machine Gun is mounted on the car (only available when the Spotter is undeployed). So in outpost form the damage output against ground targets is that of a single Rifle Infantry, just with a bit more range due to the increased height above ground. However when in the outpost the driver has access to the car's anti-air battery, able to unleash a flurry of missiles against any aerial target within range.
Spotters work well in pairs, one being deployed while the other remaining in the car nearby for decent damage vs incoming infantry. In base it's wise to set up two outposts next to each other however since on their own they might be taken out by aircrafts before being able to shoot them down from the sky. Keep in mind that for all intents and purposes the outposts still counts as a vehicle. This means while they don't require power you can't use the Repair tool (C) on outposts, the Mechanic can however repair them even in outpost form (Engineers can't interact with outposts and Tanya can't use C4 on them).
The spotter's movement speed is right in the middle of the movement speed of Light Tank and Ranger. It is only 5% faster than an APC (Ranger, APC and Spotter has exactly the same attack in vehicle form btw). The turn rate of Spotter is double that of Ranger, to make quick deployment/undeployment possible. It means it's a bit easier to escape from running into enemy groups with the Spotter compared to the Ranger. In car form the Spotter's vision is halved, being equal to for example Medium Tank or Heavy Tank. Due to the anti-air battery the Spotter can't bring along a passenger like the Ranger can, these two units have the same HP though. The Spotter's health and armor type is exactly the same in Outpost form.
I just realized that Hijackers might not be able to take over Spotters while deployed as Outposts, something I need to make sure they are able to do in the next version of overhaul (if that ever happens).
[tab]No early ground transport
Because of the strength of Architect the only way to transport him is on water (via naval Transport) or in the air (via late-game Chinook, only available once Tech Center is built). This is both to make it less easy to expand over large distances early on but also to not provide easy hiding places for the Architect (otherwise you could keep him much safer inside an APC in your expansion until he is needed).
Note however that since now can deploy a Supply Truck into a Supply Tent in overhaul (works as a temporary barracks) it's possible to use this as a way to "transport" Architects longer distances more quickly, however it adds a 500 credit cost to the Architect along with the risk of giving the enemy 500 credits if he takes out the Supply Truck in transit.
[tab]No early heavy armor
Not counting the Harvester Uzbekistan does not get any heavy armor vehicles until a Service Depot or Tech Center has been built. This is another intentional balance measure against the strength of Architect and his early expansions.
[tab]No early base defense
This has already been mentioned above but I'll just explicitly say it here that Uzbekistan does not have early defensive structures. This balances the fact that Heavy Turret is really good and, again, counters the strength of the Architect and his early expansions. Instead of having defense structures ready to place Uzbekistanian players have to rely on the Spotter Outpost's good vision to notice and respond to early attacks. The cheap and fast-to-produce Light Hinds are meant to act as the faction's primary anti-infantry response, instead of popping a defense structure.
[tab]-- -- -- -- --
So there you have it, something different for sure but I say there's nothing wrong with variation and there's no need for all the factions to work 100% the same. The old gameplay style is still around and I'm confident it's fully compatible with the new style of gameplay required by Uzbekistan. There's always kinks to straighten out but there's nothing that can't be solved. If it turns out that Uzbekistan doesn't work well because of X there's always Y to fix it.
If you have your doubts I want you to try playing a few matches as Uzbekistan vs the AI (if you can't find someone to play a proper match with). It's really fun and the new style of gameplay brings something else to the game.
If I had to figure out a way to make Uzbekistan more in line with how the rest of the game's factions work it would be to remove the Architect and bring back the Engineer and MCV. However that means there's no longer new gameplay introduced and the faction just becomes a mixture of Allies and Soviet. Where's the fun in that?