Eh, you compare a West-African Bantu to an Ethiopian, to a Pygmy, and you'll see what he means.
The first is a stocky phenotype with strong features and a thick jaw.
The latter are more gracile, tall and have more "caucasoid" facial features, likely due to admixture with Arabic people from the peninsular across the strait.
And Pygmies are feckin' tiny.
Then you've got Khoisians, who are from the southern tip, are almost caramel-coloured, and look little like their neighbors, the Zulu, who are a Bantu people who migrated down from central Africa in the 1800's.
A skilled ethnographer could probably tell these groups apart more reliably than he could sort an Englishman, a Frenchman, an Italian and a German from one another.
African tribal nations are pretty homogeneous within themselves which preserves a lot of their distinctive ethnic traits.
The reasons for this homogenity range from blood-fued to just not wanting to marry someone who can't do the proper wedding dance for their tribe's ceremonies or somesuch traditionalist rationale.