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.
Even with training the gap still persists, albeit to a lesser extent. Elite females are roughly as strong as the median male (without any extra training post drafting).
Why does the gap matter if the floor is adequate to complete assigned tasks?
There exist gaps between men as well; not everyone in a corp has to be a special forces operator! There's nothing physically grueling about pressing buttons, welding, driving, operating machinery or pushing on a joystick.