You are giving Lucas to much credit thinking he read much! I to saw it in 1977 as an adult, I said to all my friends as we walked out of the theater, it was nothing more then an Aero Flynn Swashbuckler set in the future!Well, before it opened, it wasn't clear to Lucas or 20th Century Fox that Star Wars was going to be a massive hit that spawned sequels... as difficult as that may be to believe now.
My favorite bit of revisionism is the "I read Joseph Campbell and wanted to create a modern mythology" approach that Lucas was absolutely NOT pushing in interviews done before the mega-success of the film. It's always been clear that Lucas - who was a terrible student and read more comics than scholarly classics - was far more influenced by the Flash Gordon serials, WWII dogfight flicks, Kurosawa samurai films, King Arthur, Tolkien, and Jack Kirby (etc.) than he was by Campbell's theories. But if you state something frequently enough - and pay for a high-profile PBS series about "The Power of Myth" - you can convince folks of anything.