Custom post order when using OR relation

This is a little hard to tinker with, without data to try it on.

What strikes me as strange in your architecture that you describe it as type with three possible values, but what you have it three (I guess) different keys for it. It would make more sense to me if you had single key (say faculty_type).

As it is my best guess would be try to reverse it and condition that faculty is not the remaining third type instead. Not clear if you have any entries that aren’t in any faculty though.