Kishi is not chauvinistic he's just showing some realism. It's a manga about fighting, battles, and wars. In reality men would at the forefront in those situations more so then women. Now think of it like this, in reality if you saw a man and woman in the street fighting would you look at it as a fair one on one fight or would you say that man is trash for hitting a woman. Now if you choose the latter would you be chauvinist for not think that woman could handle here self against a man. So Kishi is not being chauvinist he just not trying to be all politically correct which is one think I've always hated because it gives people a false sense of reality which could make them unprepared for the real world.