If you want a (hopefully constructive) comment, I wouldn't be quite so quick to dismiss the "They thought the Spanish were gods" aspect. There seems to be a lot of truth in the following possibility: the Aztecs didn't have a category to fit the Spanish into, and 'some sort of god we haven't encountered before' was where their conceptual outlook had the most latitude. So it wasn't that the Aztecs thought they knew exactly what they were encountering but were mistaken - more a case of the Aztecs not being sure exactly what they were encountering because they needed to expand their conceptual scheme to make proper sense of it. That must have shaped their practical deliberations in various ways.
Anthony Pagden has some really good books on this, and people like Marshal Sahlins and Clifford Geertz have written very interesting stuff on the general point (conceptual change in the face of unexpected encounters) too.
If you want a nice example of the same phenomenon, the most interesting thing about Christopher Columbus (imho) is that to his dying day he refused to accept that he'd discovered America. Because if he
had done that, he'd have had to accept what was unthinkable to him, namely that Biblical history could not be literally true - the narrative of the three sons of Noah repopulating the earth (Europeans, Asians, Africans) doesn't have room for a fourth group of people in isolation from the rest. Columbus didn't have conceptual space for the indigenous peoples of America any more than they - initially - had for him.
Sorry for the longwindedness - I'm procrastinating at work