You can hardly call Gnome and I (or the previous team for that matter) a big team.

I also agree that infantry have to look quite a bit better, even if it does risk performance on lower-spec computers. The immersion in a game, as well as it's ability to attract others (as Argh commented) is severely hampered by blocky infantry, particularly in a game which is going to be rather heavily reliant on infantry.
That being said, infantry will be very frequent, so while efforts should be made to make them look good, they should still be as conservative as is possible.
I agree with SH regarding the four sides. If you are planning to use four sides, and have committed yourself to it, then it is easier to balance when you are considering all of them (so long as you have a reasonably good plan, and are not 'going at it blind) at once, as opposed to balancing two sides, and then trying to slot in a further two sides. It means it will take longer until we see the units everyone wants (king tiger, etc), but it results in better gameplay. Everyone wants Jedi and ATATs in SWTA, but they've just have to sit it out patiently.
Besides, I quite like the idea of battling it out with infantry and light tanks, keeping things tactical until the heavy units start to roll out, in which case things start to get epic.
Just ensure that you are making all four sides different from the very start; usually the starting differences are the ones that have the biggest repercussions on gameplay further down the track.