You missed my point.
I was saying that while he is UNDER 18 (and cannot leave south america) you shouldn't sign him until the last possible moment. If you sign him when he is 14, he will miss loan opportunities for 4 years as there is no guarantee he will play for his current club by the time he is allowed to join your team.
That is OK, but it still doesn't matter much, I personally find loans not a good way to improve a player, most of my youngster who are world class now are like that cause I played them first team in league matches and they would improve rapidly cause they'd be getting like 20+ matches which is awesome for a youngster. Also he'll be more expensive at the last possible second, or someone will maybe buy him instead of you...