Botvinnik as World Champion was considered the first among equals.
Fischer had no peers.
One could also say that Botvinnik had no peers in the 1940s, when he could score +14-0=4 in the super strong Soviet Championship in 1945 (the year before it was ”only” +9 but with wins against all opponents in the top 5) and then win the World Championship with a margin of three points in 1948. It’s another thing that he did a bit worse in his seven title matches that were played when he was 40+, but still that was better than Fischer’s results as World Champion :-)
As for results against Petrosian, Larsen won his games against Petro in the Piatigorsky Cup in 1966, when the latter was much closer to his peak than in 1971. Not to compare Larsen with Fischer, who was a much greater player, but he did really well in those games.
thats somewhat irrelevant to what i asked, but still cool, so ill let it slide lol