I have some problems with your logic. The bolded is a generalization. You can't just apply it blindly to individuals as though "Everyone who is African understands Africa better than everyone who isn't African" -not withstanding that every actor with an African surname/parents is not African. And since you can't draw that conclusion, it's entirely possible for a non-African actor to be more authentic and more realistic as an African than someone whose parents are African immigrants. Also, Africa isn't a country, it's an entire continent. It's like wanting someone Candadian to play Captain America, because they'll bring that 'North American authenticity.' Obviously, no one cares about that, so I the picture that it's not about the movie, and how real it is, but about a strange need for real life to be like the fictional story, which is fine, I wish we could just separate it from the idea that all African actors are capable of something all non-African actors are not.
In my view, African actors shouldn't get any preference for being African, or having African parentage, or having an African last name. If they have experience that is relevant, it should show up as a superior performance/audition. If it doesn't show up as a superior performance/audition, it never mattered anyway.
