I expect Usyk isn't in his prime currently too. Would a 34 year old Usky who fought Joshua. Would have a good chance of stopping Fury
Prime Vitlayz shoulder got him retired against one of Super Joe's ex-opponents and prime Lewis should've been DQ'd against Michael fricking Grant. More perspective.
Both would probably knock him out but it's also not a prime Fury last Saturday. You have lots of these hypothetical threads here, way more than my football teams forum. Not sure you can ever really answer or know such questions in any meaningful way.