On a more serious note, if mid-game planets are going to have a large garrison by default, there is probably a case for doing a review of army balance and maybe adding some new army types for the mid-game. Non-Gestalt synth ascension does absolutely nothing for armies, for instance, and cyber ascension isn't great either. In theory, most non-machine empires can get Xenomorphs, but for some reason, the tech is gated behind finding a presapient species (which I've found are relatively rare, certainly rarer than pre-FTL civs).
I would also note that Mega-Warforms (and Xenomorphs) are getting a bit of a nerf in the next patch: with the increased garrisons and recalculation of collateral damage, they will end up doing much more damage to the population and infrastructure of the planet you conquer.