No one compared him to Koufax, period end of story. My point was that Koufax also had a very short time of success, albeit, legendary. The primary reason given for Munson not getting by voters has been length of career. You want to argue record, fine, but I did not mention that at all. And no, not many “top 10“ catchers had three 100 RBI seasons, three Gold Gloves, were ROY, and won an MVP award. Outside of Bench, Munson was the best catcher of his era. Tremendous clutch player, great post season stats.
Further, Sandy Koufax had four of the greatest seasons a pitcher ever had, no question. But In the five preceding seasons his record was 59-50 with an ERA of 3.65. Should Koufax be in the HOF, of course, but one can’t argue that he didn’t have a short burst of greatness with an actual longer period of mediocrity relative to a “normal” HOF career.