20-200 million, huh. Probably 1 million people per square mile in Mexico City alone in 1491 and all their sewage was deposited on four tomato plants in the back yard. Yeah, I think I follow quite well the reasoning of those who like to pretend the history of yesteryear will follow their vain imagination.
Sorry, I still see no evidence to justify belief in more than maybe around 10000 in all of Mexico at the time of their arrival.
I see no evidence to justify your vain imagination and belief, either.