Yes, prof ochieng think hemmed amonst hostile nilotes - maasai, luos and kipsigis - gusii became pretty hostile - like the northern merus sorrounded by samburus, boranas and somalis.
Growing up - Kalenjin that I remember were pretty scary sight. We had to scar our skins - all our limbs basically - with fire tatoos!! to proof we were ready to go for circumscion. Kalenjin men were just full of self-inflicted scars and scars from enviroments - thorns, wars.
I was luckly my skin doesn't have those many scars - my cousin if you look at him naked -
all you see are round scars on all feets and hand. It was like a weekly routine - you get some tree that had a cigarette like a stump, light it - and waited to burn it out on your skin - no flinching - if you're tough 3 scars per day - until there was nowhere to scar or tattoo. You waited for a week for the wounds to heal into round permanent scars. There would be rows and rows of scars....until there was nowhere to practically scar and you'd be ready to face the knife.