Did those nilotics have zande admixture or were they purely nilotic?
Looks like no Zande admixture, although this is not DNA. The Azande came from the west, arriving in the Sudan only after 1600. Today, they are mostly in Southern Sudan and the Democratic Republic of the Congo (formerly Zaire)
http://www.everyculture.com/wc/Brazil-to-Congo-Republic-of/Azande.html
The Stone Bowl cultures were Afroasiatic speakers, arriving in Kenya three thousand years ago. The Archaeological sites at Namoratunga, which appear to include a Cushitic calendar, have been dated to 300 BC and likely included Eastern Cushites.
http://www.ancientpages.com/2016/06...f-stone-and-ancient-astronomical-observatory/
http://www.travelsouk.com/dest/kenya/history.htm
"Settlement
Kenya 's Rift Valley is synonymous with the evolutionary ascent of man. It was in the African savannah that the first humans emerged and there is evidence of humanoid habitation in Kenya dating back 2.5 million years. It was not until three thousand years ago that the first human settlements became established. Kenya 's first inhabitants are referred to as the Stone Bowl People and probably originated in Ethiopia. These early settlers survived by farming and livestock cultivation, though many resisted sedentary life and remained nomadic. The main settlement of Kenya took place over the thousand years between 500 BC and 500 AD as Bantu people came from the west and south and Nilotic tribes from the north-west.
Development
The history of Kenya from this stage takes two distinct paths, with the coastal region developing independently to the interior. Inland the various tribal groups that migrated into Kenya continued to roam the land, establishing small communities, but never forming a centralized state.
Coastal civilisation
Along the East African coast a separate Bantu language and culture, known as Swahili, developed. The exposure to the Indian Ocean and the mingling of Arab traders with the Bantus created a distinct civilization. Towns grew up to allow trade and by the 9th century a number of these, including Mombasa, Lamu and Pate, had become important trading centres. Most of the commerce centered on ivory, slaves and timber to be exported to Persia, Arabia and the Indian subcontinent. The traders brought with them Islam and by the 12 th century many of the Bantus had converted.
European contact
The equilibrium established between Arabic traders and Swahili settlements was soon to be disrupted by European expansion, fuelled by a desire to develop the slave trade. In 1593 the Portuguese constructed Fort Jesus in Mombasa, to use as a centre for slave trafficking. This led the Swahili city-states to form an alliance with the Omani Arabs, and they drove out the Portuguese in 1720. The Kenyan coastline then fell under the influence of the Omani's.
The Omanis wealth and power grew as the slave trade expanded to supply the Spanish New World and British and American plantations in the United States and the Caribbean. Countless millions of Africans were taken from the interior and shipped across the Atlantic to die as slaves.
British expansion
By the time the British arrived to suppress the slave trade in 1810 it had spread disorder inland giving the British the excuse to expand their authority along the coast and later into the interior. Their decision to build a railway from Mombasa to Lake Victoria led them deep into the Kenyan interior and to the subjugation of the Massai people.
In 1896 and 1900 the British reached agreement with Germany about their zones of influence and were given the green light in Kenya. Through a gradual process of expansion and alliances, playing off different tribal groups against each other, the British had taken over most of southern Kenya by 1908, and the entire country by 1918.