"In each case: why?
In the first case, is there a fear that so many women will be killed in combat that the population rate will dip? Not even that many American men are killed in combat these days.
In the second case: if…"
It is unclear to me, how much of that is feared, rather than demonstrated. And since you have many military leadership arguing for this change, I'm happy to defer to them, rather than to politicians."