The simple answer is that the two groups were separate tribes. American Indian populations were different nations with different languages and different traditions. It's easier to understand if you realize that they were similar to the countries of Europe. The Sioux (the Lakotas) were a dominate Plains tribe. read more
The Resaru Council has the right to review all acts of the Pawnee Business Council regarding the Pawnee Nation of Oklahoma membership and Pawnee Nation of Oklahoma claims or rights growing out of treaties between the Pawnee Nation of Oklahoma and the United States according to provision listed in the Pawnee Nation Constitution. read more
Actually I'm finding out the they are significantly different (obviously) and in the movie they speak Lakota language (spoken by the people of 1 of 3 major divisions of Sioux) and in the book they are definitely referred to as Comanche so yeah, nice olympic leap over the historical facts from the director. read more