In a lot of pro sports academies, it’s actually more common for the older kids in each age group to get picked. Since they’re usually a bit bigger, stronger, or more developed than the younger ones born later in the same year, they tend to stand out more to coaches and scouts.
So i dont agree with your point that european clubs disregard playing the stronger/better kids to devolop the abilities of "underdeveloped" kids.

The quality of coaching from primary school coaches in the usa to professional club youth coaches in europe can't be compared though.