I play DA. The best games of that type that i have had there are Suicidal with max Minor AIs, largest galaxy, most major AIs, but with fewer than max stars. Rare or Uncommon seems best, with Abundant everything else.
The effect of fewer stars seems to be that several AIs will have substantial volumes of space, insulated from the others. They are then able to develop in their own mini-zone, yet the colony rush ends sooner and before they over-extend themselves.