Surely it's time to either accept/adopt selection across the board or scrap it completely.
The comprehensive experiment was doomed to fail the moment they allowed church schools to continue to be selective whilst shutting most of the grammars. All that happened was that the "parents who care" suddenly found religion to get their kids into a decent church school rather than the "bog standard" comp, and so many comps never stood a chance and it was virtually inevitable they'd only ever attract the poorer performing kids.
Comps will only work if there is NO selection, i.e. a level playing field, so no grammars, no church schools, and a real geographical limit on your options. Utopia where you automatically go to the local "comp" within easy walking distance. No selection at all means a broader cross section of pupils so less chance of disruptive and poor performers ruined it for everyone.
In our town, there are two poor comps - even at a time of rising population, their rolls are falling! The bus stops all over town are full of kids waiting to be bussed to the nearby city for the church schools or across the county border to a good comp (at least 10 special school buses cross the county border!). What chance do the town's comps have when the only kids who go there are from families that don't value education! It's a downward spiral.
So, either ALL selection needs to be stopped, or we do need to go back to allowing selection, i.e. a choice of a grammar, a church school and a couple of "comps" for each town or for each district of a city.
It's crazy having to bus your kids to a different county, to pretend you're religious, or to have to have your kids tutored for years, to get a decent school. We either have to accept full selection or none at all - this middle ground and fudging the situation has been going on for decades and needs to be resolved.