Having grown up as a revolver and 1911 shooter, my grip always focused on controlling the guns and making sure my thumb didn't interfere with operation and manipulation of the gun being used (and also making sure my thumb didn't get bit or gouged by the thumb latch or the rear of the cylinder when shooting Magnum revolvers

).
The original 1911 Government and a couple Commanders I learned to shoot back then all had standard thumb safeties, so there weren't any "enhanced combat thumb safeties" to worry about being bumped by a thumb. I could use the same "crush grip" shooting both 1 & 2-handed on my revolvers as well as the pistols. My thumb found the 1911 thumb safety and the revolver thumb release latch with alacrity, as needed.
Fast forward to the era of plastic pistols (and Sig Sauer's), with the slide stop levers shifted far to the rear, and some shooters were discovering problems with the slide stop levers being unintentionally bumped with a right thumb. Not with my crush grip thumb placement, though.
Sure, when I became a LE firearms instructor I'd dabbled with a variety of grip techniques to better let me help other folks, but I returned to using my low thumb crush grip because it let me use any design of pistol or revolver without worrying about thumb placement interfering with controls. That was useful for me because I was often having to shoot a variety of pistols (and revolvers, still).
Now, when older or other experienced shooters came through our range who had been trained using various grip techniques, including neutral or high thumb placement, I didn't try to "fix" their grip as long as it wasn't causing
them a problem. Sure, sometimes an occasional shooter asked about improving or changing their grip technique, and their thumb positioning might be something we'd discuss and try a bit differently. Every now and again someone discovered that changing their thumb placement (in either direction) actually gave them better control and/or reduced manipulation errors due to their thumb placement.
Different strokes, and all that. I was always more interested in them being able to controllably and effectively
use their weapons, 1 & 2-handed, under stress, than just trying to make them look like me or anyone else. Quite often I didn't even burden them with the "names" of the grip and shooting techniques, but just helped them find whatever grip technique they could best use (and satisfactorily demonstrate for themselves) if their lives were on the line.
It it works
well for someone, it works, so why "fix" what doesn't need to be fixed? However,
if it can be tweaked or refined a bit, and
that allows someone to experience an improvement they can consistently realize for themselves? Well, why the hell not? Sometimes it's not just about looking pretty or cool on the firing line, but being able to effectively achieve your goal in the midst of some unexpected dynamic, chaotic and rapidly evolving life threatening situation that may come along in the outside world.
Matter of fact, you could say I tend to use versions of at least 3 different well known shooting techniques myself, depending on the overall physical activities and conditions in which I'm having to shoot. Kind of like my martial arts.