Norgai do air out some of his worries when they were talking
One of his worries that if he surrender there is some chance that some of the Elders might be averse to that decision and would attempt a coup
Aeryon assure him by saying when the moment comes, these Elders would not have any power to change the outcome
Give them some threats, give them some benefits and these elders would be amenable to reason
Aeryon could see that Norgai could see things further away than other people.
But even if that was true, then this idea to surrender would take some courage to do. The courage that he did not choose wrong
What if Aeryon is not a wise ruler and he chose wrong? There is always that kind of possibility.
Putting the survival of the entire tribe into another hand would always require courage. And looking at Norgai, he is not the kind of person who is selfish.
He truly cares about his tribes.
