The real question is... who assigns the referees???
I have heard that the assignors pick the group. This could make the whole thing a "good old boys" club. Younger better referees are "left out" because of seniority. What a joke. We should let the coaches from each region pick the best referees from that region. At least that way, the coaches get a say in who represents the region. Since you can't ref your own region in the final anyway, it will be the "best" group not the assignors favorites.