I am no military expert, but I was in the military. I can assure you that we were never told anything about shooting to wound. On the rifle range we fired at pop up silhouette targets and we never once went forward to see exactly where we hit them. They either went down or they didn't. Although we were instructed to shoot COM.
Just to show you how ridiculous this whole thing is, think about this. In combat, the rounds are flying, you are scared to death. You are shooting at moving shapes, you are moving, you are ducking. And you think that someone is going to not just shoot back, but pick specific shots intended to only wound the enemy ? Please.
Why not start an offshoot of IPSC where you are penalized for hitting the A-Zone. Maybe you can adjust your sights so that you aim COM but hit way low or something.