I don't really think we can study Tolkien as a novelist, because I don't think he wrote novels. He identified his task as mythopoeia, and I think he was writing myths; his work specifically draws on source material that is pre-novelistic (i.e. Nibelunglied, Icelandic Sagas, Poetic Eddas, etc.). Even if The Hobbit, The Lord of the Rings, and The Silmarillion were all marketed as novels, they are anachronistic as far as the history of the novel form goes. His style is in debt to the epic tradition as well, even though prose dominates more than poetry; if you compare Tolkien's work with that of later fantasy authors, it's so different.