Generally Nandis are very proud people; more like Maasai; They can be arrogant; this long standing pride from 18th century when they were best warriors and would make everyone sing - well except kipsigis whom Nandis have never fought as they were one people - Nandis use to beat the shiet out of rest of kalenjin sub tribes like Pokot nowadays do and of course other tribes;
Marakwet are generally considered with Ogiek and such are low caste kind of people who dont own lots of cows/burn charcoal/work for others - menial jobs .As for closeness - Kipsigis, Nandi, Lower Keiyo, lower Tugen (Lembus) are very close. Moi was Arror - close to Pokot/Marakwet - they have some adxmiture with turkanas most likely.
As for Kipchoge - he is feared and revered - not only because he is talented but also because he is a TALAI.
Almost all Kalenjin fear Talai. They attribute all the bad luck to clash with them. Most althetes who get banned or etc also claim because they clashed with Kipchoge or Sang or such. Generally, Kipchoge word is final, and he is strict disciplenarian - so you dont go to his training camp and start nonsense.
Nandis dont fear Talai that much - for us Kipsigis - people will literally leave the room if a Talai entered. Talai are thought to posses supernatural powers - and can make your life miserable if you disagree or differ with them - so people avoid contact with them - unless it absolutely neccessary.
If Kipchoge appears in Kericho town and announce he is Talai from Kapsisimwa - he will be left in town alone
Talai because of that fear - were expelled in kipsigis to island in Nyanza - and they cameback - live together around kericho and Kipkelion towns are squarters. In Nandi - they were expelled and live together in Kapsisimwa - where Eliud Kipchoge and Patrick Sang hails from.
Generally people dont like Talai being around them.