Not offended at the term at all. I'd probably use another-but no less direct.

They (the colonials) didn't just ignore the nations, they actively tried to erase the past to prove that they were taking over a mostly empty land.

The Apache and Comanche were at least semi-nomadic while the Navajo mostly lived in permanent buildings made of wood, stone or adobe. All three fought courageous battles against a vastly superior force and lost. The Navajos accepted the offered treaty and honored it completely. The Apache and Comanche both had splinter groups that carried the fight on long after the main tribe surrendered to the reservations.

The only purely nomadic tribes came out of the great plains. Once they got horses (by about 1550) it was a life style they embraced and lived.

Speaking of horses, two Spanish explorations found the Mississippian Culture, even though it was breaking up at the time. Both expeditions suffered big losses (and turned loose horses and donkeys) DeSoto died on his trip and his very few survivors rafted to the Gulf of Mexico to escape. Not much history written about that.