What version of Constantine and Xanadu?
If we're talking Vertigo then scenario 2. is a stomp for team 1.
Either way team 1 wins both ways, as Zatanna is easily the most powerful and Deadman is hard to counter, and with prep only Beast can compete with John.
But Vertigo versions of John/Xanadu make it a stomp as Vertigoverse John is a prep god and Vertigo Xanadu is pretty damn powerful.