The power struggle doesn't make any distinction based on intimacy.
After Karul died, the bewildered butler received a call from the new tribal chief. He respectfully agreed on the other end and then ordered his subordinates to take Karul away. The butler was Karul's relative and naturally he was also related to the new chief - in fact, their relationship was slightly closer.
So, he quickly accepted this reality.
After all, no one wants to die.
To live.
That's the biggest reason for any betrayal.
And in terms of loyalty, it belongs to the tribe, to the chief, not to an already dead predecessor.
This was the rule of survival here.
...
After the appointment of the new tribal representative for the Karumba tribe, a ceremony was held at the base to inaugurate the new leader. The ceremony was simple since it was just a link in the tribal alliance, not a grand event. All it needed was inviting some wealthy, powerful, and respected locals to witness, and then treat them to a meal.