I thought about this. i am convinced that if i were in charge of a gun, my first need would be someone who could depress and elevate the tube and bore sight it. Second would be one who was naturally good at lift and carry, who could safely and efficiently get the ammo to the muzzle. After that, I do not think stopping the vent, ramming, swabbing, pricking the bag charge or placing a primer in the vent are really difficult skills, they just need to be done. My point was that Anderson did not need a lot of skilled gunners; willing hands would do.You've not served on a gun crew then.
Getting the charge from the magazine to a gun chest (limber chest if light artillery) is not even part of a gun drill; it's simply a replenishment of ordnance before and after combat. Getting the charge from there to the gun during combat is part of the gun drill, but not nearly the hardest part.
Not any private that could load and fire a musket could reliably fill any artillery position, though admittedly perhaps three of the seven positions could be sufficiently learned in an afternoon, and a fourth in only 15 minutes. But at that time, being able to read and figure was more than a lot of infantry privates could provide, and three other artillery positions required that.