Joe Louis and Mike Tyson both had flawless technique. Alexis Arguello always threw textbook perfect punches. Julio Cesar Chavez's technique was also flawless.
Benny Leonard suffers from a lack of footage, but he worked diligently to perfect his punching technique and cultivate his power, and there seems to be nothing he couldn't do well from that standpoint. There is footage of Gans producing knockdowns with both his left hook (on the iron chinned Nelson) and right hand. I'm not sure Louis qualifies because of the issues with his jab that Jack Johnson criticized prior to Schmeling I which Max indeed exploited. Joe's cross, hook and uppercut were impeccable, but I'm not sold on the execution of his jab, as hard and effective as it usually was. For me, Charles is the closest thing to a textbook HW Champion.
Shout out to Hopkins, who moves his feet with every shot, is never defensively out of position, and usually lands when he throws. Every body listed is also fair and true.
He has a pretty big tendency to overreach with the lead right. The only obvious technical flaw he has. But other than that, absolutely.
Usually has his right foot stretched wide, allowing him to carry himself out the back door in the event of a bad miss creating a lunge. I remember few times that his lunging right got him punished in return. Though I do see what you are saying.
Duran deserves a mention. :good Harold Johnson was good with each punch I think, though he was not the best at putting them together and mostly relied on his left hand. Had an uppercut that could knock opponents out cold and a left hook that he could throw off a jab or with the momentum of his right hand in a combination. Charles, in my opinion, had a tendency to sweep his punches but it worked brilliantly for him so I'm not going to criticize that pick.
His timing and ring smarts were such that he got punished for it astonishingly few times, but it is still a technical flaw. It would also be interesting to seem him against some of the extremely skilled MWs that preceeded him, especially McCallum, Kalambay and Toney. Those guys didn't let you get away with much. Man, those are fights I'd give my right arm to see.
In all his punches he doesn't utilise his whole body, he doesn't sit on his punches that well or dynamically shift his bodyweight from 1 foot to another to create more torque. Bad hands can be a symptom of bad punch technique too though, I don't think he ever had ATG punch technique, some of his other qualities are ATG but not his punch technique You missed something
yeah its strange he will throw a wild right hand duckand slip then bounce out with a perfect jab and a perfect right cross. his left hook was more of a slap