I just cannot fathom women in the Combat Engineers or Infantry.
Try imagining them in artillery.
I watched a video of USMC artillery, and they were humping 155mm artillery shells off the back of a truck. They were pulling them off at chest height, duckwalking them over 15 yards, putting them on the ground, then going back and getting another one.
I think they are somewhere around 100 lbs per round.
Sure, there are women who could do that. But the average woman could not.
When in a combat situation, I can certainly imagine times where that nice loader and transporter thingie is not going to be available, or you are simply in a situation where you gotta move the rounds fast using a bunch of people.