A lot of players are idiots.
Some are not.
Wheeler for example, could just ride his great stuff, instead, after failing to develop a changeup, worked diligently to develop a splitter. Why? Because he needed another pitch against LH hitters.
Why doesn't every pitcher do that?
Some can't. Many won't (a lot of athletes resist leaving their comfort zone and trying something where they may fail).
Schwarber is going the other way, but it probably took a sub .200 season to overcome his resistance to change.
I suspect Turner is going through that crucible, when "what always worked for me" stops working.
It's not just how good your coaches are, it's how coachable your players are.
"You can lead a horse to water . . . "