This strikes me as entirely unreasonable. In the first place, in any war, the majority of o those in the military, whether draftees or enlistees, do not get shot at. Even in war zones, some soldiers are more apt to be in firefights than others. We don’t rotate every soldier into a combat role just for equality purposes, despite their qualifications or lack thereof. That would be military disaster.
Second, there are good reasons for having a primarily male military and a primarily male draft, which have been discussed in other threads.
And as to conscientious objection, the law takes no account of the just war theory when it pertains to individual soldiers. Every individual does not get to decide for himself which war is just. (Would we allow everyone access to classified intelligence to help them decide?) C.O. laws have only recognized those who object to all war in principle.
Finally, on a personal note, one of our local priests just returned from military duty a few years ago. He served in a war zone and even on combat patrols, but as a chaplain, did not carry a weapon. Even he didn’t get to decide whether or not he would serve in a particular war. And he didn’t demand that his mom and sisters serve alongside him!