Is it really? They are still generally within the top 100 schools in the state so ahead of over 400 schools even on that flawed metric. School should be about more than just academic or sport measures at the top level
All that is based on is the number of band 6 results a school gets. it’s a long time since all results were published.
Unfortunately we don’t ever see any indication of where a school takes a kid, how they have improved. None of those 4 are selective academically - 2 at least have significant boarding populations - some from remote communities who didn’t perhaps have the advantage the same as Grammar, Aloysius or others.
Being in the top 100 out of 400+ isn't as impressive for those schools because they are very privileged, wealthy, have lots of resources, rich parents etc. - you can't expect them to perform too the standard of those selective schools but they underperform no question when you have view coming 70th. Shore and Kings coming 24 and 26 last year are good examples of schools that should be doing well and get good results.
I agree with the rest of your points though the way they do the rankings is flawed yet still on other metrics like median ATAR, number of high achievers, % of kids over 85, 90, 95 etc. they underperform.
I disagree with the premise of selective schools and this goes to your point that schools should be more than just academic measures.
Also correct to point out that there are a lot of boarders at these schools which is not the case at the top schools which would pull their results down but still at Shore nearly half of the boarders get over 90 which its basically on par with the day boys.