Yeah, I came to a similar conclusion, too. I think "Tomahawk Charge" (35192) might also be used in conjunction with them. At least the warrior on horseback appears more like a Plains Indian, but the fellow on foot, even though dressed in buckskin pants and loincloth, wears his hair loose but with a red headband, similar to Navaho's and Apache's - but what do I know? I'm just a white guy!
(No offense intended to anyone!)