"Token" as his name never really made sense, if you were to stop and think about it in-universe, but was clearly originally supposed to be an obvious commentary on the "token black guy" in Hollywood, and everyone watching kinda just accepted it and went along with it (further proving the point). His name being "Tolkien" "the whole time" was just retconning and to make the show more fitting to the current cultural climate the show has adopted.
*edit: typo/
Dr Janis/Lu Kim/various has a multiple personality disorder (which is not the same thing as schizophrenia). Poor Butters just has a very active imagination and basically no friends half of the time.