There's also the awkward fact that "Myrmidon" has the contemporary meaning of "a follower or subordinate of a powerful person, typically one who is unscrupulous or carries out orders unquestioningly." e.g. "one of Hitler's myrmidons."
I cast my vote for Areté (er-ruh-TAY) which is arguably the Greek ancestor of "chivalry." It means excellence, virtue, fulfilling one's purpose or potential. The Homeric heroes had surpassing Areté.
At the very least, in the rules a bonus of "Armor of Areté" should granted to those heroes who have 16 or greater in the relevant virtuous traits.