Joshua would dominate Fury, Haye would have retired him. Fury has gotten to this stage by fighting journeymen who were immensely undersized in comparison, and as stated earlier McDermott dominated him in their first encounter.
Just my opinion, but i have always said that David Price would destroy him within 2-3 rounds. His cardio is his achilles heel, but for a guy like Fury he is a nightmare. Just as big with almost unmatched punching power, Fury would wake up in a retirement caravan.