That was a cool read, thanks for posting it! Though when we talk of the history of fantasy we speak of writers, the editors deserve a whole lot of credit.Just read a relevant article The Man Who Invented Fantasy. It talks about Lester Del Rey and his role in popularizing fantasy fiction. How before he got involved in publishing fantasy fiction there was relatively little fantasy fiction other than Tolkien for adults. Also talks about how they told authors basic plot points like a singular male hero with a mentor facing a nemesis.
I daresay "a page-turning Tolkien rip-off" is about as succinct a description of The Sword of Shannara as possible.
Morris is one I need to read more of! "The Folk of the Mountain Door" shows up in the anthology "Tales Before Tolkien", where it notes Morris translated Beowulf and some of the Icelandic sagas.
The Chapter "The Men Who Invented Fantasy" in Lin Carter's (1969) "A Look Behind The Lord of the Rings" focuses on Morris and his "direct literary successor" Dunsany, and then E.R. Eddison.
I keep bouncing off of William Morris, but I'll keep trying. Something about his writing style has yet to click with me.