The question is can a photographer be creative without an encyclopaedic knowledge of the medium? The answer is of course. If you're a professional who's asked to shoot everything from portraits to food shots to sports, you'd better know your way round the contents of a studio and have gear for every occasion. On the other hand there are highly esteemed, gallery hung photographers whose output is shot entirely on a point and shoot camera (eg, Bertien van Manen). They know the limitations and possibilities of that choice and are content to work within them, in the same way that a competent all round artist might decide that charcoal drawing is the medium that best expresses their ideas, even though they're excellent with oil paint.
Some artists need a working knowledge of the photographic medium to produce their work, but consider themselves artists, not photographers. Effie Paleologou takes extreme close ups of discarded chewing gum with a large format camera and macro lens. My first job was to be highly competent with an ultra large format camera, but because it was all copy work it was the most boring photography imaginable! The application of size and complexity has no direct relationship with the quality of the output.