Too many non-Native historians believe that the remedy for the historical mis-telling of Native history is to "prove" that Native people are the same as / equal to non-Natives (esp whites) in all ways--that actually, e.g. Natives had empires and imperialism too!
To claim that Comanche or Lakota people were imperialists just like Europeans looks like justice to them. But it mangles the definition of imperialism beyond recognition, it misreads historical evidence, and it plays into a political narrative that justifies Native dispossession.