Club Leagues and National Youth Rating

[Gruff66]

My current save is Cardiff City. I have been asked to make the most of the team's youth setup. Having done some research I understand that national youth rating is pretty important in determining the order in which newgens are distributed among teams. My question is this: does Cardiff City use Wales' youth setting, as this is its home country, or England's, as this is the league City plays in?

Any help would be welcome.

 

Thank you.