About African Military Aviation

I’ve always been curious about African military aviation, particularly the piloting aspect. I hear a lot about Africans hiring mercenaries to do lots of their piloting, but do we know anything about how proficient actual africans are at flying their own jets?

I’m speaking mostly about sub saharan Africa. Do we know which african air forces use their own pilots, and which ones hire them? And are there any pictures of the pilots themselves(any picture in which you can see the pilot is fine). I’ve always been curious about this because it seems to be a rare sight to see indigenous african pilots. It is sort of a niche that interests me, and you guys seem like experts.:)

Also, can anyone tell me why so many African air forces hire mercenaries in the first place rather than just training a few of their own pilots?