Nonody knows how that translates to men's game though, where tactics and defenders are so much better. Take Romelo Lukaku for example. He scored about 250 goals in 150 official youth games for Lierse and Anderlecht before moving to play with adults permanently at the age of 16. While he obviously has had a good career, even if he the most of the tools needed to be great, just missing that one attribute might prevent a player becoming a really great one. And while Lukaku's size had a lot to do with his youth goal amounts, it's always a tough balance to decide whether trying to change a player to a more all rounded or whether to let him concentrate even more onto his strengths.
Since nobody knows which kind of team, tactics and teammates a player ends up for most of his career, it might be tempting to mould a young player into a more well rounded one. Which might not end up serving the player best individually in the long run, even if most safety first managers and clubs might prefer such a player.