I dont know the balance of your fork, but i'd compare it to the 0ad a23 balance, I'd say it only reflects the strategies the bot uses.
Persians can be very strong in the late game using cav and the according hero. This of course requires the bot to build his game accordingly from the start towards that strategy.
Mace had the advantage to get siege fast in their workshops.
Your analysis is good, but I think this should be generated from real games from players over 1400.
On lichess for example all games are recorded and are open available, I don't see a problem why 0ad shouldn't collect at least some data, like the civ.
With this https://trac.wildfiregames.com/ticket/4376 you could generate it out of the logs.