If you think the Comanche suffered overmuch at the hands of the Scots-Irish, perhaps you should read what the Scots-Irish had done to the Irish. As the saying went, when the Scots-Irish first landed in Ireland, "They fell on their knees and prayed to God. Then they fell on the natives, and preyed on them."
You argue that the Red men did as they had always done. So did the white man -- ask anyone who teaches European and Asian history. Ask any Zulu, ask any Turk or Arab. Siege of Acre, anyone? -- that was pretty stringent. Or are we just talking massacres? Five or six in Ireland alone, in a 600-year span ending 250 years ago. Which is about when the "puttings down" in Scotland, by the English, ended. And don't forget the hundreds of thousands of Cypriot pagans put to death by the Arabs in the 9th century, or the millions of Hindus killed by the caliphs and sharifs. Your average Arab imam or sharif wouldn't even get out of bed on a day when he didn't feel up to killing 20,000 Hindus.