DA,
Whilst this year is only 1 year, to be honest the only ISA school over the last few years that has really competed against the stronger CAS schools has been Oakhill. There may be the odd Auggies lower grade team that is very strong eg their 14as this year, but the rest of the teams I doubt would be really competitive, and 1 strong school doesn't solve the CAS issue.
Even Oakhill this year, who clearly dominated the IS 1sts comp, found it tough against Barker and Waves. Yes they drew with Waves, who under performed this year, and whilst played well to get a draw, the Waves had a big lead which they did not protect.
I am pretty sure the other ISA schools would not fare well at the moment v the stronger CAS schools, and that includes Cranbrook who are now demonstrating a stronger rugby program across the age groups.
I have constantly stated that I am a fan of creating a stronger 2 tiered system, but I don't think that ISA by itself solves the problem/opportunity.
So whilst you think the CAS may be boffins, I think you are over-stating the strength of the ISA based on recent years performances.
Keen to hear your thoughts and others.
Cheers.