Quick Hands, I had noted that this year Oakhill were nearly the undefeated premiers of, CAS based on them beating everyone less Trinity, and if Augies had played a few more of the CAS teams, they would have been pushing Oaks for the CAS Premiers title.
Notwithstanding, IIRC CAS cleaned up ISA in the Opens Rep Schoolboys team rather convincingly with the scores reversed in the Under 16's where ISA looked very impressive.
ISA also "call" on lads from Stannies and Kinross who would not be listed in Sydney JGP squads. I would imagine that there are a few of those boys in the Central West JGP (if there is such a beast).
St Pats Strathfield shows what can happen if a CCC type school moves from mungo to Heavensgame (late 70's I think). They have teams down to E's at least in all age groups.