All of the service calibers work or fail about the same. The modern, high tech bullet designs have leveled the playing field. And these newer bullet designs are not dependent on velocity alone to expand. Do not downplay the 9mm as it is combat proven the wold over. I carried the 9mm on duty for many years along with the larger calibers. Never felt "under gunned" with the 9mm. Put a quality bullet where it needs to go and the rest is out of your control.
Ammo and caliber selection is mostly based on personal choice highly influenced by gun writers, myths, rumors, and what makes us feel all warm and fuzzy. Some worship velocity alone and that is fine for them. As to "one shot drops" no one in mainstay law enforcement is keeping statistics as each shooting has too many variables to quantify. Choose the pistol/caliber that you shoot the best, ammo that functions well in your pistol that gives you confidence, and then practice, practice, and more practice.
Most of the modern bullets of any weight will work well. I favor the Federal HST, Winchester RangerT, and Speer Gold Dot, all of which can be found in 50 round boxes. When I carry a 9mm it is loaded with Federal HST 147gr standard pressure. Bill