Hmmm.... I remember telling you ages ago that one of the primary keys to this game is knowing how to develop players. I remember telling you that, if you were going to sign a guy like that, then you needed to feed him starts and minutes to develop him.
You ignored me. Never have figured out how to develop players. I mean...look at
Frank Sander! A starting guard that is losing ratings in BH & DEF. What the hell is that guy practicing?! On top of which, you use terms like "natural training" to describe what can only be described as "abject neglect".
As TJ suggests, if a coach is willing to make appropriate choices, then you can develop a player, especially a C or PG, with a WE between 10-15 at the start. They've got to be fed minutes very early on and you've got to make correct decisions about what to practice. It's not very hard.