[s1artibartfast]

I think it's very much unclear how much harm it does to segregate the disruptors.

How much good does it do a violent and disruptive student to have a quiet and studious one in the same classroom?

On the other hand, it's obvious how much bad such a disruptive student does to all of the other children.

Moreover, it there is no reason whatsoever to think harm would in any way be symmetrical.