Players have a general development path, they are not blank canvases. Through training you can manipulate things a little, but if you target areas that aren't going to improve its counter-productive. Match experience is always the main driving force in development. Good training schedules and coaches can get players to their peak quicker, help prevent decline, and polish players skills - but correct levels of match practice are 10 times more important.
I struggle to understand the fascination with training schedules, some players won't get near their PA whatever training you give them, s