Lord Lakely
Idea Fountain
20+? Isn't that a bit hyperbolic?
We're still missing about nine by my count (Maya, Inca, Ottomans, Byzantium, Carthage, Portugal, Celts, Babylon & Zulu). If three of them are in this expansion, then I think it's pretty hard to complain since the other six can be easily included in the next expansion pack along with semi-staples such as Ethiopia, Iroquois and Mali and a new nation of choice.
Not quite? Mali are an obvious gold-based civilization and Songhai were a cavalry civ with river bonuses. Nubia is an industry-and-archer civ. There really do not fill the same niche.

As far as geography goes, Nubia might be considered a substitute for Ethiopia, but as far as niches are concerned, it is closer to Mali/Songhai.
Not quite? Mali are an obvious gold-based civilization and Songhai were a cavalry civ with river bonuses. Nubia is an industry-and-archer civ. There really do not fill the same niche.