I find comparing the barbaric Aztec, Mayan, Incan civilization to Mediterranean civilizations insulting. To the best of my knowledge no Mediterranean civilizations practiced human sacrifices on a massive scale. Public executions and public persecutions of undesirables is not human sacrifice of a religious nature.
Nero and Caligula were pretty well up there on the scale of barbarity, slaughtering slaves, Christians, and anyone else who offended them in the public arena as part of that days’ “games”-they didn’t even do it as part of a ritual-just for the “amusement” of the cheering crowd.
Most-if not all-Roman emperors and generals carried their high-value captives back to Rome alive-not for ransom, but to keep in cages and slaughter in some inventive way as part of their triumph/victory celebration. The Romans took over Spain early on BC, and mingled with the natives there, spreading that hot Latin blood-they were not a nice bunch, and neither were the Spaniards who were/are their descendants-some would say we still are not...
Have you included in your research Carthage and infant sacrifice? A recent paper (2014) appears to show that this was an accepted practice in that society that certainly qualifies as a Mediterranean civilization.