I was thinking more along the lines of contracts for DHs. Are you going to pay a DH 20 million if he only plays the first 6 innings?
He might not play just the first 6. There would be nothing stopping Ohtani, for example, from DHing for 6 innings and then finishing the game in RF while the pitcher slides into the spot in the order that was the RF. That would probably be more usual, even, to prevent the pitcher spot from being in the middle of the order.
Now Nelson Cruz ain't gonna be going to RF, but neither should he be in the middle of any order except at Denny's.