The whole Tudor era is a fascination to me!

Technically, Henry VIII was only divorced twice, the second of which (Anne of Cleves) could have been annulled had Henry cared to place himself back under the authority of the Church.

In my opinion, Cranmer said and did whatever was necessary to keep his own head. While I obviously can’t know for sure, I don’t believe he had “deep faith” because it seems he was blown around with every new wind of doctrine, or rather, he outwardly conformed to whatever his Sovereign of the day wanted him to believe.
In answer to the OP, I really don’t think it would have mattered if Luther was a bishop, the end result would have been the same. Either way he broke his vows and created a big mess, something he even admitted to when he saw all the divisions that his “Sola Scriptura” heresy was responsible for.