Right, it works there because you've not merely reduced the importance of that symmetry, you've removed even the pretense of it
AI War is fun even if you lose, AI War is fun even if you don't finish, so razor-edge balance is simply not necessary. The only thing that needs balancing is to make sure that there aren't any legitimate choices that are always bad ones (and, in general, only very few that are always good ones).
As I have said for a long time, if you go back and look at all the best strategy games throughout the ages, whether Turn-Based or Real-Time, the thing that they all have in common is the propensity to force tough choices upon the player. Tough choices are what make strategies games so enjoyable, and gives them the replay value that (in my opinion) most other genres lack. AI War succeeds because the player is always faced with tough choices, especially on the higher difficulties, which often change based on the map or the situation. Any developer that can successfully implement this element into their game, while keeping the game play unique and fresh, will always have a good strategy game imo.
edit: By that same train of thought, tough choices are also something I believe makes life interesting as well, though I've never really thought of it that way until now. Most people seem to hate facing them, but how boring would life be without them?