That's a good point, but I am not sure it covers the whole issue. I am thinking of the Skokie shootout where the the cop was a master firearms instructor who said in an interview that he practiced a lot. He hit the perp 16 times with a .45, including two in the head and the guy kept returning fire until he got a third hit in the head. BTW, the perp was found to NOT be under the influence of any drugs.The real issue is not what pistol to carry to be sure to have a one shot stopping with a hit between the headlights, but more, how much practice it is going to take before you can make that shot 100% of the time with the pistol you’re carrying.
Some citizens change out their carry sidearm, from week to week or day to day depending on what they are wearing. For them it is difficult, to get the training and practice they need to be proficient.
So the proposition is that you have to get a pure, absolute center of head hit with a caliber that has high penetration, on a moving perp. Anything less might not get it. If someone with that cop's training couldn't do that, what chance do most of the rest of us have no matter how much we train? There has to be another solution.