I think that this is revisionist history and likely not as it really happened. Though this is entertaining I think it doesn't play well when you put it next to History. However, it is very entertaining in some ways because you know there is some truth to it. However, what is truth and what is not?
You and I didn't live then so we really have no idea at all what was really going on there outside of Buffalo Bill trying to depict Buffalo (which he helped save) and (Sitting Bull) who in the end he could not save from a war where Sitting Bull died at age 59.