There's a limit though on what a coach can teach. For example I think AWB is a more teachable example - he's got some of the tools already, and needs to develop a few others to actually be more useful (i.e. refine his positioning in and out of possession, and then also a cutback pass/cross). That's a realistic scope to ask a player to develop
McTominays a central midfielder, who's just not comfortable or capable with the ball at his feet. He can't take a ball on the turn, doesn't have much range or vision and off the ball he needs a lot of work too. That's asking a lot for a coach to teach him at the age of 24-25, when there are 20 year olds with most of those fundamentals nailed down
Then on top of that, is it actually worth the effort? We've already invested way too much gametime into him, and I'm not seeing much value out of it