"Benchmark of zero" for what? Women to be drafted in the event of a draft?
If so, should women still be allowed in the military?
Well, since the United States has never drafted anybody into the Air Force or Navy, there is no reason to think "the military" will require it now. As for the Marines, they've used relatively few draftees; 2% in Korea and 12% in Vietnam. I suspect the resumption of the draft will boost enlistments for them in both the reserve and active component, probably making up any shortfall.
Now, as for drafting folks into the combat arms, which is where the recruiting shortfall is most severe, we'd need to draft men as before. However, I think it is safe to assume that the resumption of conscription will flesh out all units of the Guard and Reserve and even most active units. We would have the option of raising both physical fitness and ASVB standards, so no drafting women into the army would be unnecessary from a manpower standpoint.