Slaves?

Ever since I read Pekka Hamalainen's book 'Comanche Empire' and learned just how robust the trade was in Native American slaves in 19th Century New Mexico, I've been approaching genealogy with the idea that I'd eventually find dead ends, where family lines would disappear, because these were the kidnapped children themselves. Instead, I'm beginning to find evidence that related family was adopting kidnapped Navajo children, precisely as Hamalainen described. And it makes a sick kind of sense too. Military defeat in the 1860's meant a one-time-only fire sale of Navajo children throughout the Southwest. Piecing this story together should be interesting.