To reiterate---if your success in a gunfight is based on the caliber you select, you've already gotten so many other problems that caliber is the least of your concerns.
David, My success in a gunfight might fall to my cartridges ability of penetrate past bone and skull. That has nothing to do with my ability to put rounds on target or the tactics I use while doing so. For you to continually suggest that "mouseguns" can cause, in equal amounts as bigger bored guns, the blood loss necessary to incapacitate is nuts.
It seems with you that everything revolves around statistics. Still you carry a gun when statistics say you will probably never need one. My adversary may not have gotten your memo that they should give up at the mere sight of any firearm. They may force me to shoot them. They may not give up with the pain. I will agree that at this point I am in deep trouble however having a gun that is harder to shoot, penetrates much less, and who's bullets cause less blood loss is only going to worsen that trouble.
I know a lady who shot and killed a home invader after taking a hit to the arm from a 22lr. One can only speculate what the outcome would have been had the bad guy been armed with a larger caliber considering that the little 22 went through her arm and into the rib cage but failed to break her humerus or puncture her vitals.