to zalman and joseph…I cannot find the “Ra-avad” that you quote. The Rambam clearly writes that these matters do not apply in milchemet mitzvah, which are the words of the Ra-avad, according to you.
I did find, however, the Radvaz that zalman referred to in that mishna (hilchos melochim, seventh perek, fourth mishnah). As I said earlier, the Poskim don’t agree to this view,as the Minchas Chinuch says.
However, even according to the Radvaz, women DO HAVE A FUNCTION ON WAR !! I am pretty sure you disagree with women being involved at all! (see the fight over Sheirut le-umi) SO, even, “leshitoschem”, why should women be exempt from all service?