I think many would use a form/subform design, with school data at the top and related courses in the subform. Could use a split form as well I suppose, but I'm not a big fan of them. New courses created or no longer offered - what you'd have to do is redesign the form, which is poor practice. Your idea doesn't allow you to show that a course that is no longer offered in School A ever was.
The more we hear silence, the more we begin to think about our value in this universe.
Paraphrase of Professor Brian Cox.