It’s a well documented fact that a group of females living in close proximity ( i.e. in a sorority house) will often sync their menstrual cycles. So I guess this means you won’t have one female performing below par a few days each month; instead the entire squad will “out of sorts” at the same time.
But as Rush pointed out, when they all have PMS, they could be a very effective fighting force....Hence, the “All-American First Cavalry Amazon Battalion”’
http://dailyrushbo.com/women-in-combat-rush-revisits-all-american-first-cavalry-amazon-battalion/