AI civs really don't like tribes/city states...

[Snåkon]

The AI in my game really dont like tribes!
They go beat them up at once. After transition to next age, new ones popped up and two of the AI's sendt everything they had and raced to see who could beat them up first.

[Römsen]

Haha, it could be worse. In my case, a tribe was wiped out before I was able to incorporate them.

And with the other tribe, I was gaining favor with the AI. We got it in the same turn. I was first. And a little later in 2nd place it went to the AI. Then the round was over and it stayed with the AI. So, being first is not always good in life...