Yes I would say nearly all Merus I have found them to be very enterprising and hardworking. That is pretty impressive. I think Merus generally have a problem with slavery or working under a boss...so they tend to want to start their own thing. Unlike say Kambas or Luhyas who just want stability in their lives.
Chukas are just Embus. Embus are kikuyus mixed with Kambas...so I would say Mbeere, Kirinyangas, Tharakas, Ichukas - are admixture of kikuyu and Kambas. The proto-kikuyu being a Muranga person- for Nyeri has lots of Maasai blood and the Kiambu has lots of Maasai and aboriginal blood.
Now Imentis - are probably close to chukas - but I find them more progressive - thanks to that education.
Tiganias/Igembes - are mixture of Samburus and Boranas - with Proto-Meru- and tend to have the pastoralist kind of mien.
So who is a meru - I think the Imentis - would be Proto-Meru.
Pundit you don't seem to understand Merus. You need to visit the region and interact with people not to rely on bar talk with meru barmaids who won't give the whole picture. Imentis make about 30 percent the tigania/igembe about 40% Chuka Tharaka will make the rest. Kibaki was loved everywhere in Meru not just imenti.
But you very true that the rest of merus are mixed with Samburu,Kamba and Borana and they seem to be more violent and retrogressive especially the northern ones.
Tigania/igembe are the most business like you find them even in somalia. imentis most educated since thats where bazungu settled. All Merus are agriculturalists and in agribusiness.