“‘Chief’ is not a Native American word, it’s a French word.”
Correct.
Brave:
https://www.etymonline.com/word/brave#etymonline_v_43999
Chief:
https://www.etymonline.com/word/chief#etymonline_v_47105
Warrior:
https://www.etymonline.com/word/warrior
chief - also a lengthy history in Scotland, which is one of the roots for the usage in new America.
One of the main reasons that Lamar Hunt named the Chiefs with that name was that the Mayor of Kansas City who sold Hunt on moving there was H. Roe Bartle and his nickname was Chief.
Unique amongst significant city Mayors, Battle was a full time Boy Scout Executive with the Heart of America Council. He had started an honorary camping society and fellowship within BSA called the Tribe of Mic-O-Say. His tribal rank was Chief and that was his nickname for decades: Chief Bartle.
The team, of course, saw the traffic opportunities with tribal headdress and the like, but Hunt confirmed this numerous times.
I was privileged to meet Roe Bartle a few times. His program was credited with creating a district with the highest percentage of Eagle Scouts in the country.