Post 2 is spot on. However, the one way you might argue this would be to point out that by the fifteenth century AD, the Aztecs ruled over the surrounding peoples by force and terror, which found its ultimate expression in the human sacrifices you mention. In fact, some Aztec wars were fought with gaining captives for sacrifice as a major, if not exclusive, goal. When the conquistadores arrived, they found willing allies among the subject peoples of the Aztecs, for obvious reasons.
Are you trying to argue that the Aztecs "dominated" their subjects because of the human sacrifice? Or are you trying to say that the Aztecs themselves were "decimated" (had their population greatly reduced) by these sacrifices?
Either way, I don't think you can say this. The sacrifices were typically people taken in battle with other people, not Aztecs. To the extent that the Aztec population dropped, it was largely because of diseases brought by the Spaniards, not because of sacrifices.
Litteacher8 thank you for accepting my point, this question was posed as a result of my recent knowledge that over 80,000 aztecs were sacrificed in tenochitlan