you got fucking kings, Torygg, Helseth, living gods of the Tribunal.... under an "Emperor"? who puts some garrisons around but does.... what exactly?
theres an "East Empire Trading Company"? whats that do?
it kinda seems like a holy roman empire, kinda seems like a regular roman empire. they've got knights, dukes, but a Legion...
yes i know the answer is technically "these jackoffs just made it up as they went" and don't care a lick about political theory but this is exactly the kind of excercise that makes fun speculative historiography
There were technically a couple of empires. You had the Allessian empire, the Reman empire, the Septim empire, the Mede empire, and a handful of interegnum empires in between each major dynasty/era.
But ya, the dragonfire covenant is a big reason you can point to for why the empire was relatively stable. Having the head god of your pantheon literally backing your government and in the process keeping the devils out, is damned good for legitimacy.