Look at football (tournaments, friendlies) all these countries playing and then we does want to show up with 2-6 weeks of local training to beat these teams. Unrealistic.
Tough reality. Some nations have as many as three (3) separate teams up and running right now within the U20 and the U23 age band.
Mexico for one....but one could argue that they have a deep enough talent pool to field three sides
The reason why Mex. is and probably will always be the best in football, because football is #1,2,3. Yes they play baseball, basketball, even American football. A couple good tennis players and race walkers and quite a few excellent middle and lite weght boxers. Football is king,queen, prince in that country. They have a big talent pool. They have an excellent football league. probably the best
organized league in this hemisphere. They have excellent stadiums that can rival those in Euro. Their football league get a massive amount of sponsorship. They play with passion. And least but not last, they have home advantage in the high altitude.