Having seen more than a few people shot, and killed, by all common calibers: placement is king. After decades of experience, arms/ammunition makers know that .30-.45 handgun calibers work best for taking bi-pedal targets because they have highly comparable and consistent penetration and damaging capability. The cartridges offering comparable penetration have fairly different "ignition properties". I.e., .40 is "snappier" than a .45 which has more "push" than a 9mm. Bottom line, and easily demonstrable: a decently performing shooter will be faster and more accurate with 9mm than with .45 or .40 from the same platform; equally, the 9mm offers the same or greater capacity in a smaller frame (which is easier to control).
Don't bring logic, actual experience and field data to this discussion, damit!!!
45ACP is a hard hitter like 45-70, and shooting twice is silly.
9mm is what women-folk use to qualify, aka closest thing to airsoft.
oh.... and tanks!!!