I think that it makes sense to use a smaller number of categories for a smaller number of names. There are only 573 total names under "African names" in the database. Splitting it up into the individual countries would make really small categories, no? The individual country information is included in the name descriptions.
I understand it's frustrating when there's only a small amount of entries for the culture/s you're most interested in. I think looking in the submitted names is a good idea. There are plenty of reasons why a site might not have completely equal global coverage. You might want to try specialty African naming resources.
edit: This is a good resource for Zulu names I think.
https://www.africa.upenn.edu/afl/zulunames.htm
This message was edited 5/20/2020, 9:24 AM