How do they look in terms of raw scores? Those are the rankings that matter.
Raw score rankings do not as a rule measure the output of schools, they measure the involvement of parents, which will always have a much larger impact on child outcomes than the schools do. Schools are an important marginal add-on that we want to make better, and in order to measure their value add we have to find ways to account for parental involvement and remove it as a factor. Socioeconomics is a passible proxy for involvement.