I can't think of a single RTS that had good team game balance and a proper competitive team game scene. 2v2s are usually alright, but anything beyond that turns into a clusterfuck.
Warlord Battlecry III. Shame so few heard about that game... 16 faction - still balanced.
Cossacks 1. Best balance ever - ya, mirror design but that's the point, mirror deisgn is a way better option if you want to have balanced game and enjoy the game.
Or even Alexander.
Good old RTS...