I wouldn't spend greens to train players who are 22/23 years old.
18-21 is when they make the best gains.
Nope, not anymore and especially not when those 22 and above players are ones, who have some skills really high and others really low.
If you then find the right drills that train the lower skills with maybe 1 or 2 higher in it as well, you can have much success training them. More than bringing in a young guy and trying to give him his first drills and improve white skills.