While DC (formally National Allied Publications) started publishing comic books in 1935, starting with New Fun #1, of course, it was their Action Comics series that helped DC achieve considerable success, and Marvel (formally Timely Comics) was then founded shortly thereafter, having started with Marvel Comics #1 in 1939. While Golden Age DC had their most successful big three of Superman, Batman, and Wonder Woman, I don’t think that Golden Age Marvel’s most successful big three of Human Torch, Sun-Mariner, and Captain America is quite as comparable. It would probably be a better comparison to compare Fawcett with DC, as Fawcett’s Captain Marvel was apparently so popular, that he outsold Superman in popularity for a time, so would it be more reasonable to posit that Marvel more likely became DC’s biggest competitor in the 1950s or 1960s?