I’m pretty sure that you have some say in which school your DC goes to, and no one is forced to go to KB’s school.
Parents get an illusion of choice, and pupils may get a place there who didn't really want it. You don't really get a say in it.
Michaela is by all accounts a small school, it has 698 pupils on it's roll, spread evenly that is 100 pupils a year. (7-13) My DC's school has 300 a year (years 7-11 only). It is much easier to implement some strategies on a smaller scale, that just won't work with larger numbers.
As for it being all deprived pupils, it has 23% eligible for free school meals, compare that to one of my local schools which has 43%, my children's school has 29%.