So whats the deal with all these african civs having all these gunpowder units anyways?

I dont know exactly what everyone gets, but im sure multiple of these african civs gets hc, bbc and cgs. I guess its okay to give them cgs though, just so they have a way to take down fortification on land, but thats about it. In any case, these civs are strong in their own ways, idk why they needed gunpowder, the mezoamericans cope just fine without it,

Im not an expert on history , but im quite confident the africans didnt go around raiding tribes with gunpowder back in the days, oh well.