I would've gone in a different direction. Increase the unit values of military, then you would have a greater variety of numbers to chose from without it becoming overpowered. If 4 pts is the base value, a 5pt unit is 25% stronger. If 10 pts is the base value, a 11 pts is only 10% stronger.
If you began with doubling all values atm, then tweak from there, you can fine tune the militaries of each race. Could also introduce more variety with the soldier: 2/2, 3/1, 1/3, 4/4, 3/3 or whatever.
Question: Will Sabatoge mods continue to increase chance of success?
Rest of mechanics seem fine.
1 additional request: Reduce base attack time to 14 hours (instead of 16). This will help the casual player to get in his 2 hits per day without having to set an alarm or run a setup specific to his limited amount of time for utopia. I dont think the game wants to cater towards 24/7 people (these ppl generally burnout) nor towards once-a-day loggers (that would destroy the current player base). But changes should be put in to allow ppl to login in the morning and evening and still remain somewhat competitive with the rest of the server.