@Boo Girlie BoomBoom
Altan's tribe is actually pretty small compared to most other nomadic tribes, mainly because they have very high mortality rates since no one thinks dying is a big deal. They have a tendency to trade service, specifically protection from the big carnivorous thingys out there, with other tribes for materials.
The Noble thing is interested because as tribe they don't believe in "born nobility", since you can't have a good grasp on one's spirit at birth. So if the two met as children it would probably just be cultural confusion. Realistically Altan would be very young if they would have met since she's a few years younger than Daeli.
For the last bit, Altan's people are quite haughty and probably don't give a crap about what other tribes do, but their internal laws when it comes to murder and manslaughter is vastly different, mainly they don't make a big deal about it, especially if it's unintentional. Basically Altan would be confused why the banishment even happened because like, accidentally killing people isn't a huge crime from her view as a child.