I think I'd feel better about that if there were more game books doing that with Africa or parts of Africa. Also, my general reaction to the fantasy Europe books is colored by the fact that I already have a good understanding of the roots of the genre. I don't have that for any part of Africa and so can't tell what's being made up, what's being warped (or mangled), what's being transplanted, what I could make deeper with more research, and so on.

Does that make sense? It means that the book is bearing a much bigger burden than a standard supplement does.