Chivington deserves your admiration under your previously announced criteria: “they won by the complete and utter destruction of their enemies.”
As does Lt. William Calley.
But if you want to add new criteria, as an after-thought, to exclude Chivington for some reason I can't stop you.
If you want Chivington or Calley on the list that is your decision. I didn’t include Genghis Khan or Scipio Africanus either.