I could arbitrarily decide that Joe Grim would beat everybody on Vitally Klitschko's resume with equal justification.
You don't need footage of a fighter, to assert that they would beat somebody, without presenting any evidence. That is all that you are doing.
Kids these days are better boxers than Sharkey. Primo was sadly more of a circus freakshow than a true fighter. Sharkey wouldn't beat Bivol never mind the giants.
He also beat Harry Wills, end one of the best streams of dominance in heavyweight history. Also Tommy Loughran who had been competing with elite P4P boxers since he was a ternager Plus George Godfrey, Max Schmeling, Young Stribling, Jack Delaney etc.
Jack Sharkey was a better technician than anybody in the heavyweight division today, with the sole exception of Usky.