Honestly, trying to figure out the reading order for 'one' manga chapters is a bit of a rabbit hole, and I'm not entirely sure there's a single definitive answer that works for everyone. The series has had different serialization formats and even alternative versions, which complicates things. Some people swear by the original webcomic order for its raw pacing and initial vision, while others prefer the jump to the redrawn version in 'Shounen Jump' because the art improves so dramatically at a certain point. I've seen threads where fans argue for switching at chapter 84, which is when Murata's redraw of the Hero Association arc kicks off in earnest. But then you've got the 'Murata Version' redraws of early chapters themselves, which sometimes add new content or slightly altered sequences. I personally read the original webcomic all the way through first, then went back and read the Murata redraws, and it felt a bit disjointed but gave me an appreciation for the evolution. If you're a newcomer who cares more about polished art and consistent narrative flow, starting with the Murata redraws from the very beginning and just following the 'One-Punch Man' manga on Viz or the Shounen Jump app might be the most straightforward path, even if it means waiting for some of the later webcomic material to be adapted.
That said, the debate isn't just about art quality. The webcomic by ONE is way, way ahead in terms of story, delving deep into the Monster Association arc aftermath and beyond. So if you binge the polished manga and hit the current 'latest chapter,' you're gonna have a choice: either wait months or years for Murata to adapt the rest, or jump over to the webcomic. That jump can be jarring because the art style shifts back to ONE's simpler sketches, and some minor plot points might differ slightly. But the core story is the same, and the webcomic has this frantic, hilarious energy that the more cinematic manga sometimes smooths over. My advice? Read the Murata version until you catch up to the most recent manga chapter. If you're desperate for more story, then seek out the webcomic and continue from there, accepting the art shift as part of the charm. Trying to interweave them chapter-by-chapter is more of a completionist's project than a practical reading order.