BTW, I wonder how come Native American names are usually either common American names, or NA names rendered into English; i.e. Running Bear. Are there instances of NA names in the tribal language?

Assimilation of native peoples was both a popular movement and governmental policy for many years in first half of the 20th Century.
It is my understanding that officials would not accept tribal or native names and insisted "American" names be used for school, jobs, etc.
That is one reason most older Native Hawaiians have "American" first names and Hawaiian middle names. Further I've been told Native Americans had an "American" name (Joe, Jane, Bob, Betsy etc.) and a Tribal Name used among their own people.
Times have changed, thank heavens.
If I have been misinformed I await correction in the expectation others will leap into the breach.
wow