Well done to all those boys.
But it is important to understand what those teams are.. They are not a Schoolboys side of old.
You can only be selected in those sides if you played in the schoolboys tournament this week - so that excludes anyone selected for Waratahs, Waratah White, Reds, Reds Grey, Force, Brumbies or Rebels sides and playing in the ARU Academy tournament (as well as anyone injured) - something like 5x23 + 2x15 = 145 Schoolboys + U18s., and accounting for the lack of depth in some teams, maybe 75-100 Schoolboys who feasibly rank ahead of these sides.
So in a position where a particular association (GPS or CAS) is quite strong, its quite feasible to miss out on association selection and make it to the Schoolboys team.
But it also shows the issues with starting the CAS season so late (only 2 of 5 games played), whereas GPS had played 6 of 10 before selections.