Evolutionary biases simply aren't relevant structurally. While men do exhibit more violent behaviour, it's been since the invention of the state that violence became a tool and not a concern. The vast majority of violence has for a long time been organized, calculated state or political violence, not instinct-driven agression. The latter still exists, but pales in comparison.

Put another way, if you took almost any society today and made everyone women, you would not see a major decrease in violence, as the vast majority of violence done serves structural and material reasons.