Weapon use seems to have been a big part, and is that really a "major physical effort"? Unless you fire the rifle at the end of an obstacle course...
The fact the women seem to have done as well as men wrt hit probability using the M4 but not the heavier weapons, really point to physical limitations and not lack of skills.
The casualty evacuation issue is also a major issue, men can carry both sexes, women will have trouble with many men, and will be completely unable to move the bigger men...