I think there should be a setup like practice PVP but in ranked PVP. That way, you could know exactly who your up against. Just a thought. :D
It's not like that to keep Ranked PvP unpredictable and fair. If you knew who your opponent would be, you could set up your deck accordingly, and have an easy win. It's also a way of encouraging players to come up with strategies for every school, and build a multi-purpose setup to fight them all with.