All of this leads to the old joke, "What do you call 64 Cheyenne in a room?" "One indian."
The linked article unfortunately bases its conclusions on "self-identification," which is problematic. When the federal government sent the tribes billions of dollars in COVID relief money, suddenly there were newly-minted, self-described "indians" crawling out of the woodwork trying to get a check.
Also realated, there's currently a bunch of people on a reservation outside of Seattle who are being kicked out of their homes because they're not tribal enough. The tribe changed its definition, and because these people are from a related tribe up in Canada, they no longer qualify.
/Friends with a lot of indians. Subscribe to two indian newspapers. And yes "Indian" is correct. It's only white people and city indians who embrace the term "Native American." Rez indians call themselves "indians." Proudly.