This is a lovely history of the various threads of historical speculation around native american sites in the Mississippi basin.
What i find difficult is attempting to place the Aztecs anywhere except Mexico. Why bother? Also we are all messing with time and place. The Aztecs were extant circa 1200 AD through 1600 AD to which we can add two or three centuries of prehistory. There is an apparent lack of linkage to earlier building that spanned at least several hundred additional years.
The most important time and place happens to be over a thousand years earlier when the Atlantean world set of a global trade empire that surely founded the Olmecs and operated copper mining in the Great Lakes and plausibly the Andes as well. Yet this only tells us to look. Evidence remains scant.
Much more important is the Wyandot report that the builders of the mounds fled to Mexico in the face of a barbarous uprising. This works as archaeology shows us an elite in these stations and surrounding local populations not building mounds for day to day living. Yet they could all be latecomers to the Mississippi basin.
It all feels like an echo of the Global Bronze Age Pyramid culture pursued after the collapse in 1159 BC with small local mounds that grew as populations grew. As posted earlier, think cargo cult.