Hang on: this is a long one.
Well, I pulled out my old copy of Mystic Warriors of the Plains to see what Mr. Mails had to say. It was less helpful then I thought in this matter. Most of his writing is about the various plains tribes in their golden age before overwhelming White contact, but a few thoughts could apply, depending on as much flavor as you wish to add.
• I would name the standard member of a War Band a Warrior, not a Brave. Although Mails does not use the term "Brave", I see no problem calling an inexperienced young warrior a Brave.
• The most common term for a War Band leader would be Pipeholder. Plains Indians were steeped in religion, and the leader was the one who carried the pipe. His authority was absolute: at least until the fighting started! Alternately, you could call him a War Leader.
• War bands could be led by what Mails calls War Priests, known for “visions and astuteness,” not necessarily as healers.
• The term “Chief” is as good as it gets for generic English translation. You might consider that one of the minor War Chiefs, who would be a special character of renown, could lead a small War Band.
• Each War Band used experienced warriors as scouts. They often camouflaged themselves with wolf skins, so were sometimes referred to as Wolves. I agree the term Scout would be useful for a Warrior who worked in that role for the US Cavalry.
• I would separate Holy Men/Priests from Healers/Doctors. According to Mails, and other sources like Grinnell, they were two different offices. So you can have a Shaman/Priest/Holy Man class, which are mediums of communication with One-Above, and in game terms could boost a Band’s morale; and a Healer/Medicine Man/Doctor class, which deal only with illness and injury, with both a herbal and religious approach (i.e., driving off bad Spirits). The term “Medicine” derives from earlier times when the French called an Indian healer a médecin, or doctor. English-speakers substituted the word medicine, which came to be a catch-all—and generally inaccurate-- term for all aspects of Indian mysticism, religion, and healing.
• According to Mails: “All experts agree….that a wounded warrior became an absolute and totally reckless terror.” This aspect could be recreated in a special Berserker-type rule. Alternately, this could be a special class by itself, since occasionally a warrior, for whatever reason, approached battle fatalistically and fought fiercely with no regard for personal safety. Not sure what you’d call this type of warrior.
So here’s what I have so far:
War Chief Exceptional warrior and leader
War Priest Exceptional leader and better-than-average warrior
Pipeholder Normal leader of a War Band: Better-than-average warrior and leader
Warrior average Plains Indian
Wolf Exceptional in stealthy movement, average warrior
Brave Inexperienced warrior
Scout Average Plains Indian who occasionally works with the US Cavalry
Shaman Exceptional religious figure who boosts morale/performance but is a
below-average warrior
Healer Average or below-average warrior with healing ability
Berserker??? Above average stats in every category (See above)
I’m obviously only scratching the surface here, and all may not agree with what I’ve written, but at the least it should be food for thought.
The morale of a war band is fragile at best. According to Mails: a war band would flee after a few losses “because their medicine helpers had misfired somehow, or else they had misread the signs, and to stay would be to invite a worse tragedy still.” A war band “took any losses as a bad sign, and were glad to find an excuse to call it a day.”