Kudos to JT for spotlighting the second part of your inquiry. It does help clarify why Ring Magazine named Louis as the top puncher in boxing history. Perhaps the more appropriate question would be who's in second place.
I don't know if you checked out the "and stopped after" part when you listed those Dempey opponents, but if so he has quite a few as well.
I did, but making repeated use of the edit feature on that post would have been disingenous at best. (I'd already used it once to delete Firpo.) Miske becomes the one remaining standout on his resume. As I've stated before, I'm convinced that the hardest punches of Dempsey, Max Baer and Marciano, were harder than Louis's hardest individual shots, but Joe's combination punching and accuracy did enable him to score knockouts in situations where the other three would have had to settle for points verdicts.
Pacquiao stopping Morales during their rematch. Morales had been in plenty of wars thorughout his career and never stopped up until then. Not my number one choice, but worth a mention.
Exhaustion. Any excuse whatsoever. Thats what seperates the kryptonite chins from the solid ones. A fighter gets stopped ten times during his career, all coming after the 8th round in fights where he was exhausted. His trainer says years later "his chin was great, it wasn't the punches that beat him it was the exhaustion". I'm sorry, but having a good chin aint just about absorbing bombs over the first 8 rounds.