The Indians were unbelievably cruel and brutal to their enemies. They were not the "noble savages", as they are so often portrayed. They were heathen, cruel peoples.
Not really. Just people. Their culture accepted this as normal. Just as the Europeans accepted the verdict of the Inquisition to burn heretics as the stake. No more savage than believing slavery was a viable economic system. No more violent or cruel than the English sentence for treason.