Nubia...is kinda hard to place. Geographically I would guess being in Nile flood plains kind of make it North African, and the close cultural ties to Egypt support it. So I guess it's taking the second North African spot, but sacrificing Maghreb presence to double up on Nile pyramid builders doesn't sit right with me. If we can have nine African civs, sure, the third North African slot can be Nubia. But if not, North Africa #2 needs to be in the Maghreb, as one of Carthage/Morocco/some Berber flavor.