MumTryinHerBest I'm just dipping in and out of this thread but to answer a couple of the points you addressed to me: Bertrand spends a vast amount of time arguing her point, she's well able to spare a couple of minutes looking at a list of super selectives on a league table list and picking some at random, if she's minded to follow anything up. It's elementary.
Second, HTs of grammars will obviously have relationships with most or all of the primary heads in their area, or extended area, I've no idea why you'd think any different. That seems to be to be yet another opinion plucked from the sky, but not based on how things actually work.