This sounds good in theory, but in practice 2e and 2f will be the problem classes that everyone will be trying to escape, including those immigrant kids whose parents are more upwards-mobile and who pay attention to their kids education.
Yes, but on the other hand, the same thing is currently happening, just on the scale of parents moving out of school districts with "problem schools" that are mostly determined by a higher migrant percentage. Thus accelerating the formation of migrant and lower class neighborhoods and upper class suburbs.
Providing different classes at the same school would at least allow some contact of those different groups of children, and in a similar fashion, contacts between the adult population.
