Ketchel's problem is, that we actually have clear footage of him fighting. Which means, we don't have to rely on the testemony of old-timers, who saw him in the flesh more than 110 years ago. We can judge him with our own eyes. Benn early ko.
Have to agree with Bukkake (the poster, not the practice of). I've seen a few decent length, decent quality clips of Ketchel and he looks absolutely awful. He worked on a farm so, despite his lack of muscular definition, he was probably very strong and mentally tough but that's about it. Balance, speed, technique, defence, co-ordination Benn looks light years ahead of him. The whole fight would resemble the 8th round of the DeWitt fight. Not pretty. As I have said before, different sport. Ketchel helped get boxing off the ground but nothing he does in the ring or in training resembles anything that you would expect to see from a modern fighter.