I agree with metal - it sux but what would work better?
So, you would be happy to have players that are OK, but not the best the country can offer in the team. We know with allot of players you can train them as much as you want, but in the end they will still be the OK players . They will improve, but possibly never get to the level of others.
I think the system we currently have incorporates all of the factors. They scout the country, keep tabs of certain ones. Have camps,train, discard and pull up players as required. Have more camps. The top players for U20's are generally playing ASB. They cover the whole country, not just Auckland.
Whole of Football aim is " to have the best play with the best". not train and try and make the mediocre into the best the can be and exclude the players who are the very best.