Goodbye,
the thing is, you can say 'there are a relatively poor performing swathe of...' about any group of schools:
There are relatively poorly-performing private schools (only 1 in my area performs better than the comprehensives)
There are relatively poorly-performing comprehensives.
there are relatively poorly-performing secondary moderns.
There are relatively performing grammars.
[By 'relatively poorly performing', I mean in comparison to how decently-performing schools of that type perform given a similar intake]
What I don't understand is why you want to roll out the grammar system, if you acknowledge that a significant proportion even of the current 164 are relatively poorly-performing, rather than deal with the relative poor performance of a similar proportion of comprehensives?
I do genuinely believe that many schools perceived to be 'poor' are simply those with more challenging intakes, but equally, like you I agree that there are schools that could be better. The effort - and extra money - should be provided to do this, not to change the system.