Or do you just want to point out the bad and throw in the towel on the question of how it can be fixed?

Man, that's for wiser fucking people than me. I'm not going to pretend to know the best outline to split up and combine African ethnicities within contiguous borders. I studied pre-modern European history, not post-independence African geopolitics. I don't have the expertise necessary even for a rough sketch.

And honestly, I don't think it can be fixed at this point, at least not across all so-afflicted countries. The damage is largely done. In the past 60 years, institutions have been established, internal migration has intensified, nationalism cultivated, etc. Most of Africa is probably pretty stuck with the problem, and has the unenviable task of making disparate peoples cooperate within a single polity. It is possible - but it is also difficult (see: India).