This is kind of missing the point.

What I'm saying is there are records that have either been ignored, neglected, or destroyed.

In Mali alone there are millions of historical documents [1] that have not been suitable explored. The Meroitic [2] script that contains historical records is still poorly understood

1. https://en.wikipedia.org/wiki/Timbuktu_Manuscripts

2. https://en.wikipedia.org/wiki/Meroitic_script