No doubt Feller's reputation overshadowed Lemon to a greater or lesser extent, but taking them as pitchers on the same staff, Lemon didn't become a regular until Feller's time as a dominant figure was nearly over. Counting from 1948, Lemon's first big season, Lemon won 192 games; Early Wynn won 163 games for the Indians; Mike Garcia won 142; and Feller, 108.
Lemon got off to a slow start and didn't last well into his late thirties, so his career numbers are mostly not really good. He was in the top three among AL pitchers in wins eight seasons out of a nine-year stretch, yet he's only 100th in career wins. A couple of approximate contemporaries, Milt Pappas and Billy Pierce, are both a few slots above Lemon in career wins, yet between the two of them they were in the top three on the seasonal leaderboards only three times.
Warren Spahn is well known for having gotten off to a slow start because of the war, but Lemon missed two years to military service himself and was also delayed in maturing by his late conversion from third base. So Spahn ran ahead of Lemon in total wins every year from their respective 25-year old seasons on. Judging them strictly by their standing on the wins leaderboard -- a very superficial comparison, but viewed over the long run of several seasons a good simple approximation of their standing -- Spahn remained in the top three with great consistency until he turned forty, while Lemon never did it after 35 and won only six more games from 36 on.
Sandwich in five more big seasons of the kind he was putting up in the early '50's, and Lemon still would not quite match Spahn for longevity, but he would have 300 wins and be a lot better remembered.
I had forgotten that, the famous "Spahn, Sain and pray for rain" poem notwithstanding, 1948 was one of the worst years of Spahn's career. Not a bad year, but worse than almost all the others.
“Money, money, money; that is the article I am looking after now more than anything else. It is the only thing that will shape my course (‘religion is nowhere’).” - Ross Barnes