The wrong kind of details: the components of wonder (aka lmp's rant)

[Naaramare]

If the Hobbits are Tolkien's mediation for Middle Earth, what mediates for other authors, such as Howard, Kay, LeGuin, etc.?

If by mediation you mean person-to-whom-the-reader-may-relate-to, Kay's five "real world" protagonists are his mediators, I would think. They are, after all, from our own world.