Excellent post! Just one caveat: Marciano, as I know you will agree, was not primarily a counterpuncher; he stood in front of you, feinting and ducking, but always seeking to swarm in, whereas Frazier was a bit more aggressive in that, bobbing and weaving, he always came straight into you. Here I would point out another --overlooked-- weapon Frazier employed to good effect: a swift, stinging ramrod jab, which, as with all of Smoke's punches, was primarily designed, not so much to find the range, but to punish you.
Frazier was the better swarmer. His speed of pressure is unparalleled at HW. However, Marciano's unrelenting attack was more consistent and vicious in pace than Frazier's, not in speed of pressure, though. Frazier seemed to wane in his consummate punching against Bonavena. You can't blame him for slowing down in the gruesome FOTC, however, if Marciano had Ali on the ropes for such a sustained period of time I believe he would've sustained greater output and damage on his opponents inactive body. However, Frazier actually got Ali on those ropes for such an extended period of time due to his speed of pressure. Marciano doubtfully would have been able to get Ali in such a vulnerable position on the ropes for as long. Regardless, he would've thrown more leather in my view. Marciano threw 100+ punches against Charles in 15th of their first fight. Amazing Charles lasted, but his technical prowess and boxing ability are at a ATG level. Frazier-Ali III at the time broke the records for most punches thrown in a HW fight. I don't know when that type of statistic started to get counted, but had Charles-Marciano entire film existed maybe that would still be the record. There's also a valid question of the effectiveness of such punching. Frazier was clearly more accurate and sharp in his punching, landing on the chin more often. Marciano was more powerful and damaging to breakdown an opponent's body, but maybe not to catch them as cleanly. If he did land in the perfect spot, then it was likely lights out. Not quite the same devastation and power took place with Frazier's best punch as it did for Marciano's Suzie Q. I also think Marciano was a bit more durable, besides having better stamina (To which Frazier already had terrific stamina). Frazier was a bit more focused on the body, partly due to trapping his opponent quicker than Marciano could. Rocco still probably was more oriented in hitting an opponent anywhere he could, rather than focusing on attacking the opponent's body and chin (Although ideal), which Frazier did, which helped him break down the opposition in a more calculated way.
:goodYes, frazier had other tools but all of his movements were about getting the hook working, he could shorten it, lengthen it and double it up without losing power. Half of his defence was having that left hook timed because everyone who fought him had to adjust their style around it. If he wasnt landing he was not winning. Both marciano and Frazier had the ability to throw the other mans game. Marciano’s great asset was he looked so crude, but he was always thinking and dangerous from all angles. Frazier was running on a rhythm that was programmed. Both were equally effective against the very best opposition. I would say Frazier depended more on being pin point sharp, where as marciano could still be effective if he was only landing at half force because he was so much more confusing to face. At his 67-71 prime frazier was as effective as any real ATG though.
Might as well flip a coin, but I think Joe was a littler better. Faster hands and more accurate punches. Those left hook counters would get you outta there. But there have been some great posts about Marciano in this thread.