Sara, that’s a really interesting post. Frye quotes Genesis 49:22, “Joseph is a fruitful bough” recurrently as one of his standard examples of metaphor, which is a bit odd in terms of his view of the story! What you say suggests that he read the Joseph story more “realistically” than he usually does with the biblical text. On that level, Joseph is not the most appealing character: he “brought a bad report” to Jacob of the handmaids’ sons, and he follows this with the egocentric and even blasphemous dreams. (When I teach this story in my Bible and Literature course, I find very divergent responses to Joseph.)
Frye would obviously have been aware of the theory that the Joseph story represents the interpolation of Egyptian material into the narrative: I wonder whether he thought it was discordant with the rest of the story?
You mention that the Joseph story is generally highly regarded, and I also wonder whether Frye comments anywhere on the greatest retelling of it, and one of the great modern works inspired by the Bible, Thomas Mann’s Joseph tetralogy. I think this is one of the most neglected masterpieces of modern literature – perhaps partly because of its forbidding length.
By the way, Samuel was another biblical character whom Frye did not like!