Other people here can answer much better. Take a look at the thread called "Crow - Group Photographs"
You will see early photos of Crow Scouts riding bareback. Sometimes just a Crow warrior sitting on a blanket on the horse. Later, the Crow warriors have western saddles. During the ceremonial events the Crows would carry a special ceremonial blanket tied to the front of their saddle - again if you look at the photos you can see this.
Art should be creative and individual. I hope you will keep "respect" an important part of your work. And by the way - I am not Crow.