If you use other students for that problem instead of other teachers, you'd swap a budgetary problem for a bootstrap problem.

The upshot for this is that the benefit is as much for the student doing the teaching as the one doing the learning. Teaching has a much greater effect on _retention_ than listening reading or even doing, which is the majority determinant underlying the primary school curriculum.

There are a whole host of secondary benefits to this (as well as lots of logistical challenges): the students are doing something useful, teaching, and we pay teachers if you wanted to expend budget there I suspect it would have great effect, as would any other form of ~~bribery~~, I mean, incentivisation; socialising, especially if you have the teaching being done across different classes (which you would want to do because you want the teacher to know more than the student).

If we had budgets that allowed for one teacher per ten students, I imagine many problems in education would already be solved.