In measuring grips strength, which is a good proxy for general strength, 90% of females producing less force than 95% of males. In other words almost all men are stronger than almost all women.
An army that can't mold recruits to perform all the duties expected of a soldier is no army at all. Boot camps include a healthy amount of physical and endurance training.
If that factoid were at all important then the military should use grip strength to determine who to draft, not gender.
Some of the best pilots ever have been women. Whatever the population distributions are, if a woman wants to join she should be permitted to, with no presumptions about her limits. You risk never finding some of the best talent if you shut out women.