The early explorers noticed the Indians on the East coast took the hair and scalps of their victims as war trophies.
Digs have found skulls with scalping scars as far back as the 1100 AD on the High Plains.
Then there was that proof of cannibalism in the South West that the Indians refused to accept, so they blamed it on a roving band of Aztecs invading the area.
Many years ago OETA Oklahoma Educational TV had a program on how movies perceived the American Indian. IMAGES OF INDIANS. In it, one of the hosts claimed Indians NEVER scalped or tortured people. Later digs proved him wrong, wrong very wrong!
Everything you said is spot on. I’ve been a student of anthropology, especially of the American Indians, for 50 years, plus I’ve lived among them, and their predecessors’ ruins, going back even before that.