Marksmanship shooting and combatives shooting are completely different kinds of shooting. Different aiming, sight pictures, trigger pull, etc. And... different positioning. I'm not talking about shooting from cover, or any ridiculous "dance steps in the open" nonsense. This is about Counter-Offensive pressure.
Every industry seems to have its "dirty little secrets" - things that aren't common knowledge, false assumptions, facts that run counter to common sense, etc. In the world of handgun training, one of our dirty secrets is "There's stuff that sells and there's stuff that really saves lives". You really need to know the difference.