Well, Ruiz, Rahman, Moorer and Maskaev are all very decent wins, but I think putting Dempsey in the Lewis, Byrd, Ibeabuchi bracket is very reasonable.
Of course Dempsey was much more successful, it is not close in all time rankings. But given both styles AND size, it would be very tough for Dempsey. I mean muscular size, & delusion is evident in anyone who says they would be remotely similar in weight if Tua was lean. Tua, several inches shorter than Dempsey, was overweight, not fat, at 243 vs. Lewis. he was not at all overweight when 20 lbs. lighter. Tua's measurements, legs, arms, chest...logically could not be that much enhanced by fat. Given his bone structure & whatever training he did, he was heavily muscled while Dempsey was leanly muscled, a massive difference. Thing is Dempsey would win by a KO or likely not at all. Tua for all his faults had a devastating punch, great endurance, & a granite chin. So at their peaks likely Dempsey loses. This is no knock against him, their peaks were separated by around 80 years.
dave wins fast it's a lw who was to wild leaving himself open vs a person who hit real hard and jumped on his opponent who didnt fight from a distance