The Riekling Chieftain will feel that you are strongest of the tribe. He will challenge you regardless of your choices.
It is time to fight the Riekling Chieftain. If there are other Rieklings, they will join with you and attack their (former) chieftain. If oyu head to the mead hall after this, you will be able to recruit one of the Rieklings to be your follower.