Total annihilation took a completely different approach of having factories instead of races. I only know TA-like games through Zero-K, but factories introduce

Total annihilation took a completely different approach of having factories instead of races. I only know TA-like games through Zero-K, but factories introduce a lot of diversity and perhaps less imbalance risks because players always have the option to go for a mirror match-up (i.e. choosing what is considered the best factory for the map being played). Some game designers claim that Blizzard's uses races to keep players interested by creating imbalances. The idea being that you keep players interested by making slight changes all the time to respond to alleged imbalances from the players.