He's basically tbh a more realistic version of Mr. Satan. I was thinking about this the other day.
Mr. Satan is not even Pilaf Saga Goku level (lol) and is basically a scrub (like a normal MMA fighter). But everyone thinks he's a beast/strongest ever.
Realistically Mr. Satan should be much stronger then the level given to him by Toriyama TBH given:
(1) He won the 25th Budokai. Even though the competition let's say is weaker you had guys like Giran, Nam, King Chappa, and Pamput (etc). Preliminary fighters were also pretty beast (giant bears, bruce lee wannabes, etc even in the manga but way more so in the anime). Realistically there is no logical way unless the entire world of Dragon Ball has amnesia everyone would have just forgotten about the 21st-23rd. So realistically Mr. Satan should be like King Chappa level and have some superhuman ability to make it consistent. I think Toriyama just forgot completely about the 21st-23rd...which is....pretty fucking bad tbh considering all of us are FANS and still debating this shit 30years later yet he forgot in under 10-15.
(2) Given this Buggy is basically a more realistic Mr. Satan and a more logical one. He is way stronger then the normal human and is superhuman (like East Blue wise he's a beast) but is a joke to New World Pirates. So he is what logically Mr. Satan should be (a joke to the top tiers but still superhuman, but Satan is a scrub even to regular top tier humans like King Chappa....guy can barley beat a GUNMAN). So I think Buggy is basically an improved Mr. Satan. I don't think WG knows he's weak and thinks (like Satan) all his victories (he was a Warlord) are legit. And he has Crocodile and Mihawk as "minions" now.