Another state institution. In other words Utah as a state institution owes it to the state to play at the very least other state funded FBS programs. Taxpayer money should benefit the state not just one institution- this would arguably include BYU too. I don’t think it’s a violation of “church and state” either if there were a large Muslim, Catholic, Protestant, secular, etc. fbs program it would be in the State’s interest for that school to do well. Requiring Utah to play BYU or Utah State with at least 5 road games every 10 years with each school guaranteed at least 1 home game would have a compelling secular reason and it doesn’t really entangle the state with religious beliefs.