First, I hate unregistered people who post! If you've got an opinion, fine - Just put a name on it like the rest of us do. (This way we, all, know whom we're arguing with.)
Second, Yes, the 38 Long Colt is the cartridge that was used by American forces in the 1899 Philippine insurrection. IIRC, it replaced the 38 S&W which, apparently, was an American military cartridge.
Third, IMO, Evan Marshall takes himself much too seriously. I don't place a lot of store in most of what he has to say. His viewpoints, too often, come across to me as being rather priggish.
Fourth, Somewhere in the, 'this or that caliber blows 'em away' theories room should be made for the sheer PAIN of being hit with a bullet. Years ago I was shot across the ankle with a 22 caliber bullet - ouch! The impact knocked me off my feet. I very much doubt that it was expansion, energy transfer, cross-sectional density, or bullet weight that knocked me down. Instead, it was the impact and the pain! Years later I was shot across the right side of my head. (Yes, I know - this explains a lot!) I didn't go down; but I did stagger backwards and fall to one knee.
Finally, There does seem to be a, 'magic corridor' about 2" on either side of the backbone, and running from the base of the neck down to the groin. Put a decent bullet in here; and you've, pretty much, got your man. As I type this I'm troubled by a recent reading of the 1986 Miami shootout. It certainly appears that the combatant's ATTITUDE has a lot to do with the physical and emotional ability to absorb terrific carnal punishment. I guess, with the wisdom of old age, I have to conclude that ALL pistol calibers KILL; however, it's only the occasional WELL-PLACED shot that, ever, STOPS. I'm not sure, 'What' the answer is; but, I can say this; 'I will always remember Peter Hathaway Capstick's accounts about his use of a 12 gauge shotgun and double 00 buckshot to stop wounded charging lions DEAD in their tracks with head shots he made at inside 15'. Wow!!! I'd have to say that Capstick DEFINITELY put this technique to the, 'acid test'.