The Navy , Coast Guard, and the Air Force do not fire weapons nor learn to field service weapons in basic training. They constitute ~50% of all service personnel. I never even saw a weapon except for the sidearms on MP's during basic training in the Navy in the late 1980's. I did my basic at Great Lakes. I did not even have to do so in Marine basic which I had to complete after finishing my Navy A School. Marine basic was at Camp Lejuene. I think ~50% of all recruits never even holding a weapon constitutes "huge numbers of people in the military" and since learning to fire a weapon does not constitute becoming a trained killer I cannot see how the minimum number of military personnel who are not trained killers could possibly be less than 60%. It's probably more like ~75%.
John Thornton