Since it can be any one of those empires and John Knew Rome could not defeat the Parthians. And Parthians were part of the known world Rome therefore did not rule the world in the same sense as anyone else. Alexander ruled the known world Rome did not. Therefore your analogy fails. And since it fails with secular Rome how much more does it fail with Catholicism.
Here is the fact that proves all your arguments are simply empty arguments. John uses the PRESENT TENSE that demands that a CITY PRESENTLY known to John was ruling over the kings of the earth! What city known to John could that be other than Rome?
You have divorced yourself of common sense to say anthing other than Rome!
Pleeeeeeeeease use common sense in your arguments! You don't know what John knew or did not know about any other nations! Alexander did not rule over the whole world or even over the known world but he was the greatest world power at the time and ruled over the kings of the earth, many literally and those he did not could not overthrow his empire.
The Medes and Persians were part of the known world when Babylon came to power but it still ruled over the kings of the earth as the Medes and Persians could not overthrow it.
When the Medes and Persians were the dominant world empire the Greeks did not challenge it but the Medes and Persians ruled over the kings of the earth as the dominate power. It cannot be denied that Rome ruled over the kings of the earth and the Parthians and Germanic Tribes could not overthrow it.
The fact still remains that John used the PRESENT TENSE which demands that a CITY known to John was PRESENTLY reigning over the kings of the earth and there was no other city that can fit that description WHEN John wrote other than Rome - period - end of story -