I agree with both of you.
On one hand, civ4 solution of introducing artificial united "native american civ" was heretic abomination. On another, tribes were diverse enough for one of them to hardly represent all (but way too many to put them all in the game). On yet another, to be honest, most of North American Indians don't meet criterias of actual civilization...
Thus, NA natives have been always problematic in civ series. Everybody (except youtube comment section alt right lunatics) wants to see them in the game in some way, but every way to include them sacrifices some "civ values" in the process.
I know three NA groups which meet criterias of settled civilization.
1) Cahokia (also known as Missisipi Civilization or Mound Builders) which is mostly obscure and I am not sure if we know any of its leaders good enough
2) Cherokee after adopting European inventions, but they are geographically close to Washington so they mess up with hotly desired "geographic balance" of civs
3) Pueblo adobe builders who were going to be added in BNW... And then it turned out tribal elders oficially disagreed on their people being displayed in a video game
So current solution is to grab any big, fresh NA culture and put it in the game as an abstract representation of North American Indians