the men don't accidentally start acting like crazed nutters, but are fed drugs which strip away their better (civilised) selves.

Absolutely. This is the big point for me - that the women deliberately set out to prove their own point, by whatever means necessary. Which makes me wonder why they (the women on Gloria specifically) were so intent on rescuing the men in the first place? They insist they can't just let them die, but then go out of their way to provoke behaviour that "justifies" murder.

There's that point here about civilisation being paper-thin, but that's hardly restricted purely to men. We don't see the women on those drugs and so have no way to tell if they'd be just as bad

A telling moment is Andy/Kay's reaction to the fight with Bud; "I felt it! I felt physical anger, I wanted to hit him. Woo-ee!". Clearly, the ability to feel aggression isn't lacking here; its absence is cultural, not biological. Given the right trigger, these people too can be aggressive. I wonder at the fate of Andy/Kay in the longer term, when the ramifications of that fact are contemplated.