Avira > Nazir 59
thanks. I don’t think this is a full answer. Gemora learns that women should not carry weapons because men go to war in the context of prohibiting cross-dressing both ways. So, this is not saying that women should not go to war, but it is about dress code under assumption that weapons are for men. if a society has women in the Army, then this might not apply. And if Norks introduce longer skirts for their warriottes, there will be even less of a problem!
As to Yael’s choice of a peg, Gemora again means exactly that – she did not want to violate Tzniyut rather than prohibition to fight. Otherwise, she would not be allowed to hit him with anything. Pshat seems to be that Yael is sure of her ability to bring her peg from outside and use it, while not having her own sword (see above), she would need to get access to Sisra’ sword (who might wake up hearing the sound of his weapon) and then risk using a long heavy sharp device she never used in her life. Lesson – know yourself and use what you know. Maybe she did not want to steal from Sisra for no reason also!