A lot of these are glorified and complicated "rock paper scissors" games. Each race has a set of units, some air, some land. Most can attack anything but others are specialized and can only attack land or air. Some have really long range, but other hindrances to balance them.

Yes this is a mass simplilfication of the game. There is a lot to resource management and production capacity to train/build/grow/call in more troops.

I cannot speak to the competitive side of it.