Now depending on the pitcher’s physique and “on board” flexibility, then comprehension level, you’ll get varying degrees of what looks like … " got it!"
Some pitchers, because of their girth and body makeup, sense of balance, and maturity seem to be more flexible by first leading with their upper body - in particular their belly and torso, while bringing the hips around as an after thought. And no matter how hard one tries to convince these pitchers to do otherwise, they don’t. Nevertheless, some of these people seem to have success with what feels comfortable, but their longevity is short lived due to the strain that the shoulders and arms take upon themselves.
Reasoning out the health benefits of the technique that your trying to coach here is so important to proper development and all the other things that fall in line with said same.
However, no matter how hard one tries to coach a pitcher in proper techniques - under pressure and strain of the moment, a person will revert back to what they feel most comfortable with, regardless of how right or wrong it is. This “throwback” to what’s comfortable is the mind’s way of reassuring itself under stress. So when coaching this part of the pitcher’s progressive movement, don’t under estimate this portion of the experience.