Frazier only had eyes for Ali in 1971. I think after that point Frazier was a part time fighter looking for superfights with Ali..even ten years later his "comeback" against Jumbo coincided with Ali's Berbick fight. Each man has an era. Joe's was Ali's exile years. After that he was "outside" of his own era. He paid his dues back then. Sonny and Floyd would look good on the record but like you say when should Joe have fought them?
It would be 3 years before Frazier climbed back in the ring with Ali ,after FOTC he kept his distance all the time he was champion and could dictate who he faced. Frazier could reasonably have fought Liston when he avoided the WBA tournament, it made sense to give him a miss because Sonny might have had enough left to kick his butt before he got into gear in the later rounds.. Patterson would have been cake for Frazier by then ,and a bad match up for Floyd at any time imo.
Frazier mowed down the hwt division was undefeated and then proved all time toughness taking the punches he did from Ali over 15 rounds to win. Most who were not around do not realize Joe was considered unbeatable after that bout. Frazier was a fighter with limited overall physical abilities but if he were to have retired after fight one his stock would have been much higher than it actually is today.
I was around and I would have bet on Ali to beat him in the return even if was prior to the Foreman fight.Ali didn't trust his legs or stamina in their fight encounter.Frazier wouldn't find him retreating to the ropes quite so much when he had more rounds under his belt.After FOTC and his time in hospital Frazier was in fact very beatable. That's why he milked the title for 2 years fighting two unranked , and undeserving challengers.
After Frazier beat Ali and before he lost to Foreman the general thought by the experts was that Frazier was unbeatable. If he had retired at that point and did not have his two disasters against Foreman he would be only the second hwt champion ever to retire as an undefeated fighter. His ranking as such would be higher not lower than it is today. I would think he would make most top tens ATG hwt champion. Joe looked a world beater going 15 rounds at high output non stop along with taking a battering to best Ali. No one could say he did not have ATG characteristics based upon this bout alone.
Yes and no. He won the championship legitimately by beating Ellis. Along the way he beat strong contenders.....Chuvalo, Quarry, Bonevena, Mathis. On top of this he beat the retuning former undefeated champion in Ali. If you then top this all off with that all time win vs Ali and retire undefeated you do in fact have a strong ATG top ten hwt champion. It's easy to discount this just looking back at Fraziers Post 1971 career however if that never occurs one needs to understand the mindset of the boxing community as of his win against Ali. At that time his stock was at an all time high.