yes. though I honestly would rather it's not even there, there was really only long distance trade, and one unsustained attempted invasion across the Sahara, and not by West Africans. my knowledege of it is mostly limited to my reading of ibn Battuta, but afaik there was virtually zero marriage/diplomacy between West and North Africa. At the risk of being called ethnocentric again
I really don't think they are necessary for a game that is about medieval Europe/Middle East. Some tax modifiers in the North African cities where the trade routes go, representing the trade would be my ideal representation of West Africa's impact on the Med. in the time period.
That said, as long as they aren't screwing with North or East Africa/Egypt, I don't mind that West Africa is there, but the oases (at least as they are now) do just that.
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Aasmul, idk if this has been reported or not, but there is another duplicate barony, b_minden, in c_tecklenburg and c_schaumburg