I don't believe one school can cater well to all abilities, because the spread between the bottom and the top is too wide. It is wide because of already existing inequality on the ground, the social divide that exist in UK. They often quote Finland and Sweden as examples of good comprehensive education. But these countries have socially homogeneous societies. Nothing like in this country.
All educational systems struggle to accommodate all ranges of abilities when a wide divergence exist. In countries like Germany, Holland, France they simply leave the bottom 15% behind. They don't allow the bottom x% to affect the education of the majority. It is not fair but at least they are clear what they do. In this country there is denial.
The top 5-25%(?) already took care of themselves via selective and independent schools. They left the majority behind anyway. The real problem IMO is that the remaining comprehensive sector insists on aligning on the lowest possible denominator and bring the middle down to keep in touch with the disruptive bottom x%.
Yes, there is a handful of comps that succeed, but it is impossible to replicate and scale up. There isn't enough inspirational teachers/ leaders for all comp schools.
I say take the bottom x% out into a really good well resourced, expensive education adapted to their needs. The society already pays a lot of money for them anyway in benefits, housing etc. Put the money in their education. It could be vocational, but it doesn't have to be. The problem with bottom x% is that they would struggle to learn any skill if they don't have the ability to focus, to persevere, to believe in themselves. If you can teach them wood trade, you can teach them English and maths as well.