That whole line of BS also assumes that the opfor will A: care about their wounded, B: have medical staff present to do so, and C: all the other guys around the now wounded troop stop and take the time to evac him in the middle of a fight.
A lot of the people who spout this are also members of the 30 cal mafia, and bitch that that's why the poodle shooter is anaemic. Well, if that's what is desired, why bitch about it?
If you want to go with that line of thought, we should just issue orders to the first unit in contact (and the bigger the better as you will see) to just surrender. That would tie up way more than two guys per friendly to detain, search, process, and transport. The opfor would rapidly have their fighting ability diminished due to being overloaded. At that point, we shove in a follow on unit to whack the distracted opfor. Easy.
Of course, just like the "shoot to wound" BS reality would seem to dictate otherwise.