Isometry? Really? This is probably about as necessary as unnecessary brain surgery. AFAIK isometry wouldn't work with the standard tilesets anyway, it would involve far too much work to adapt them.
keep using fake iso as Starcraft or Dune2k should be better, with those view you dont need to worry about vehicle tilted that will force you to use made engine to support voxel/3d model in the end.
One reason why I don't like isometry is that it grossly fucks around with what you think you see on-screen. N/S distances and speeds, etc seem different than E/W speeds; yeah, it's easy to get used to, but I still don't like it because it just looks odd regardless. It's probably the worst style for RTS, at least in my opinion.