The Naming System in Kenya

Traditional communities of Kenya used the patronym or matronym.The Kikuyu used 'wa' to mean 'of' so, Kimani wa Mumbi is Kimani (male) son of Mumbi (female). The use of the mother's name among the Kikuyu was a result of polygamy, where a man would have more than one wife, sometimes upto 10. Using the mother's name was important, moreso to the father who needed to know which wife gave him which son, or daughter.

The Kalenjin use 'arap', as the Maasai use 'ole', while the Meru use 'mto' sometimes just shortened as M'. So if my Meru name is Kiraitu M'Murungi, it means that I am Kiraitu son of Murungi. And you read the name as Kiraitu Mto Murungi, not Kiraitu Mmurungi.

Even though Kenyans adopted the English tradition of using the paternal surname, after being colonised, most - if not all - did not use it the English way. Look at the example below to clearly understand:

A man called Paul Kimani Njuguna,
is the son of John Njuguna Gitau.
And John Njuguna Gitau,
is the son of William Gitau Kamau.

Clearly, the surname in the English concept should be Kamau for all, from Paul, to John. This discrepancy was brought about by the fact that even though the Kikuyu, and many other Kenyan communities, adopted Christianity, and hence English customs, one's given name was always a Kikuyu one, or an African one. The English/Biblical name is what was, and still is referred to as the 'Baptism name' and one did not get that until after going to church to be baptised. This baptism could happen two weeks or even months after one was born. That did not mean that you had no name. One had the African name. Still, under the influence of the missionaries, the baptism name came first i.e. before your African name, and so your first (African) name became the middle name, and your given (baptism) name became your first name.

To make it simpler:
When a child was born, Africans already had their naming systems - maybe after seasons, conditions, ancestors, family, etc. - so if a child was born today they would name the baby, for instance
Wambua mwana'a Nzeki, i.e.
Wambua child of Nzeki.
(Wambua means the child was born during the rain - mbua.) This is an example of the Kamba way of naming.

So, after Wambua was old enough to take to church for baptism, the name Wambua would become his middle name, preceded by say, Paul. And that is how Paul Wambua Nzeki would come into existence, according to the colonists.

By this argument, it would be safe to conclude that Kenyans did indeed name like Ethiopians, where in Ethiopia the name:
Hamerti Paulos Gemechu,
means that Hamerti is the daughter of Paulos, who is the son of Gemechu. I come to this conclusion seeing that Africans in Kenya did not really consider the baptism name when naming their kids, and neither did they use their father's name (last/surname). They merely used their first (given/African) name. Otherwise, we would have been able to trace our ancestors a long way up the tree by just a name, the family name. Only a few communities like the Luo do that, hence the Obamas, the Nyong'os, etc.