If one talks about "ball" or FMJ ammo, then the .45 is one of the better rounds simply because it opens a larger hole for blood loss (despite the round nose FMJ being a poor design for such).
When it comes to modern JHP ammo which expands as designed, the .45 does have a slight edge because the total volume of disrupted tissue is still a bit larger than smaller rounds. But this assumes
identical bullet placement in identical targets which is seldom the case. To get an idea of the kind of damage and trauma a .45 JHP can cause, watch either this video (Federal HST)
or this one (Speer Gold Dot)
Only the combination of penetration and placement to hit the very few and rather small vital organs -- is what makes the injury immediately fatal (brain steam, aorta, and I assume, heart).
You omitted the central nervous system (CNS). Any round that can reach and damage the spine stands a very good chance of shutting down your opponent if you can hit that rather narrow target. Making a head shot isn't a guaranteed stoppage, but usually works.
When it comes to COM shots, a retired Coroner told me that most of the "instant" fatalities he'd seen (that didn't involve a CNS hit) involved a solid hit in the top 3-4 inches of the sternum. Specifically, the region of the aortic arch (above the heart). Medical diagrams show that the esophagus, trachea and aortic arch are all crammed in this area so a miss of the heart's main output artery can still impact the main ventilation system or the ability to swallow, which can make breathing very difficult. Many times all three of these major are damaged by a bullet or bone fragments. In those cases, the subject almost immediately stops being aggressive and concentrates on trying to stay alive. Damaging the aortic arch is kind of like ripping out the all the oil and fuel lines at the same time. Blood pressure drops in seconds.
Other hit points flank the spine between the neck and groin. The main arteries that move blood through the body are on the back wall of the body. If you disrupt these, blood loss is rapid and dramatic.