This is faulty logic. With a feral pig, the ethics of hunting say you don't try to dispatch it with a single 9mm hit. Just shooting to drop the animal, one or multiple 9mm strikes to the vitals will definitely kill a feral pig.
Don't see it that way. There is a HUGE difference in hitting a pig with a 9mm and a .475 Linebaugh, or. 500 Maximum. One kills like a 375 H&H rifle, the other like a 22lr. While we can't really quantify why, the difference does exist.
The common factor is that both move very quickly, and, may charge. If the BG gets both arms up, to shoot at me, and, I happen to shoot the BG's arm, I want a bullet that's going to blow down the arm, go through the target, and, not loose much velocity doing it, and exit. I just measured myself, and, that would mean 3 FEET of penetration, from hand to back. I support that need for penetration, deep penetration by the number of hand hits that the FBI guys took in that firefight. It appears hits to the hands and arms are much more common in a firefight then we want to admit, and, that we train for.
Shooting with your off hand appears to be a much needed skill to develop.
Fackler shows penetration of 27" for 9MM ball. That might, or might not be enough, if I have my BG shooting at me, with hands up. That's marginal for a feral hog, in particular if it doesn't go down, CNS, with the first shot.
Also, pigs don't wear vests, and, the .475 might get through a vest, might not. 400 grains at 1350 fps is going to give the guy one heck of a bruise, even if it doesn't penetrate, which I think it would.
For real world LEO, the service calibers aren't much different. Hollowpoint loads all penetrate pretty much the same, and, in many situations, none of the service calibers penetrate enough.
In fact, ball ammo, even 45 ACP ball ammo doesn't really penetrate THAT well:
So, the real answer maybe setting up a situation where the officers have maximum chance of hitting their target, with ball ammo, with sufficient penetration.
Sounds to me like submachine guns would be a good issue weapon for such situations...
Italy, and many Euro countries agree with that conclusion...