Thanks for your informative reply. I feel as you do that even with the dire need of manpower at the front lines, a percentage of the staff had to stay back and tend to things. It also stands to reason that some folks were much more valuable to the regiment yielding thier trade skills than a firearm, they may have been assigned to less hazardous duty during battle.
Your reference to modern warfare and those caring for equipment and fuel is equivilant to my reference to those caring for the animals and wagons. It was their mode of transporting supplies, artillery, and ammo in that day.

I will look into the reference materials you posted.

Thanks again