Yep, I remember those days. I was there in 75, again in 76 and stationed there from 79-82. Brass pickers were a common sight as were the roach coaches. I suspect they still are.
By the time I left Benning, I was sure two Roach Coaches were organic to an infantry platoon.
Funny thing, when I got to Korea, I discovered pretty much the same thing. When a platoon left post for an exercise, two moma-sans would fall in behind. I thought the average infantryman was heavily burdened until I saw the crap these moma-sans would carry. Two, maybe three ice chests full of cokes and goodies to sell the troops.