> Take a look at a map of Europe around the 1600s with all the free cities and sovereignties
To be fair, those European states, groups, and entities were still extremely interconnected (in comparison) and shared societal, cultural, and religious traits. They viewed themselves as part of a single "Christian civilization," at least in very broad terms. I don't think such an argument could be made for North American societies.
And yeah viewing all Native Americans (I mean in the 1600s, not necessarily now) as belonging to some single "nation" seems like a purely European projection. That seem pretty superficial and essentially erases all of those diverse cultures (which is what is what ended up happening...).