The Gilman interview is rather like a private conversation in code between two savants, and is certainly impenetrable if you haven't read at least one of the works under discussion. I'm not sure I detect any Graves-Frazerian absolutism ("As a scholar, I know that The White Goddess and The Golden Bough are flights of fantasy..." GG says at one point) in what after all are works of fiction. But not fiction in the Gravesian style of dramatising a historical or mythological theory. Moonwise at least has no ideological designs on the reader as far as I can see; it doesn't seem to be saying "this is how things actually are, or were". It's a ripping yarn, a very long prose poem or a costive folie de grandeur according to taste.