It’s Akira Kurosawa’s Yojimbo except with Americans and guns. Definitely worth checking out.
And Yojimbo's really Dashiell Hammett's "Red Harvest" except with samurais and swords. Then there's "Fistful of Dollars", which is Yojimbo and Red Harvest, but with Clint Eastwood, a bunch of Italians, and six-shooters.
"Last Man Standing" is the only version that's at least set in the same era as the book.