A prime Tye Fields or Sugar Valuev obviously would mop up the floor with either of these guys. Wilder has to fight someone with at least a pulse first before we can evaluate him. Like George Foreman said years ago about his comeback opponents: "They were eight days off the respirator not right off of it." Carnera beat a couple quality fighters but we don't know if it was on the up and up since his career was controlled by the mafia. I'll say Wilder poleaxes the Ambling Alp in about 3 rounds or so.
The only decent opponent Wilder has beaten is Malik Scott and that looked like a quit job to me. Wilder has the physical tools to beat good heavyweights but he hasn't tested them against anyone who can ( or will ) seriously fight back. Until he beats someone like Stiverne, Fury, or Wlad I'm going with da' Prim'
Wilder has done nothing yet to suggest that he would be able to beat Carnera. Obviously we need to wait and see what happens when he steps up.
I think without steroids Carnera easily. With steroids Wilder. Wilder basically is an extreme ectomorph , glass-chinned and not too talented.
Wilder can punch, but he has fought nothing but stiffs, which is major red flag. And it's criminal he is fighting for a belt. For all of Carenra's mob influence he does have a few credible wins on his ledger. Until Wilder gets at least two legit top ten guys out of there on the level the pick has to be Carnera.