It's on a random-large, 5 players total.. I knocked out one AI completely (before any Marza hit level 6) and had some great battles. I took his homeworld with 13 capitals ranging from 3 to 5, lost 3. Plowing through minefields with no scouts is fun, too. Just set Dunovs on auto-cast and chaaaaarge!
Now I've got 5 of each Marza/Dunov/Kol, 1 Akkan (I was trying to go for the no strike craft achievement too, but I forgot and built some hangars because pirates jumped in from a weird angle once.. but that's why no Sovas), 3 of the Marzas are past 6, so killing enemy fleets isn't much of a problem. Mopping up a second TEC (got his homeworld already), then got 2 Vasari left - dice rolls didn't give me any Advent.
Can't build starbases either since building the cruiser would screw with the all-capitals achievement
All thanks to that bug in the 1.1 beta that erased the achievements file.