In the interest of revealing the truth, I can't let that go unchallenged. You are confusing pistol philosophy with pistol acuracy. You brought up the subject, I didn't, and it requires a rebuttal.
When you shoot on a range, you are shooting at a target that is only a few thousandths thick...in other words, two dimensional. In real life, we shoot at three dimensional targets. Therefore, your great definitive hits on paper may translate as a secondary hit on a three dimensional target.
During a long career as a police firearms instructor I have investigated many shootings and attended several autopsy procedures. So, part of what I'm saying is from the classic literature on terminal ballistics and part is from personal observation.
There is only one hit on a human target that is a one shot stop: a bullet through the brain stem makes all motor function cease. But, if the brain has sent instructions to the muscles, an action begun will be finished. Many gunfights are a dead heat; the winner gets the first definitive stop hit.
In a hit where an oponent is facing you directly, the bullet strike must be on the bridge of the nose to penetrate the head and destroy the brain stem. Then, all motor function ceases immediately.
Unfortunately, your opponent may be at a slight angle to you, making even a precise hit miss the brain stem. And, that's the reason I demand the utmost precision in point of aim and point of impact. It seems counter-productive to willfully introduce any amount of parallax.
If you build a double target carrier with the back target 8" behind the front target, fire from a point to the left and to the right of your head on position ;you will get the exact dimensions of miss due to angularity. A one inch miss means a total miss. Oh, yeah, your opponent will die, but it will not be an immediate stop.
And, since you brought up the s;ubject of executions: I know a thing or two about them, since I saw the aftermath of mass executions of POW's during the Korean war. The act is never at contact distance, unless it is the first one inflicted. The splatter is gruesome. Most executions are conducted at about twenty feet. How much parallax do you have at 20 feet? Add that to the original 1" miss dimension due to possible angularity.
As I said, either type of laser is useful, but I prefer the internal kind for the above reasons; any parallax is vertical and the bullet still strikes the brain stem. When it comes to pistol sights, the best is none too good. Unless you have no intention of using the pistol for its intended purpose. Every defensive use of a pistol is an execution or an attempted execution, in effect.