I don’t know about levels of intellectual rigour, but I can tell you that studying film requires understanding narrative and story telling the way literature does, but film does not require a mastery of the written word, however it does require an understanding of the language of film. there are visuals to think about and many creative decisions to make in film production, plus the technical side is deeply complex. film production requires planning, managing, and organizing teams of people and budgets, where literature, creating and studying it, usually won’t require more than readin, writing, and research.