It seems more like a federation of independent states that share such a strong common culture (ruthlessly imposed) that it looks like one thing but it may have been 3 (or 4) 'triplets'.Not like East/West empire at all; you're right, it was a split, not a united empire.
I don't think we have anything like it to compare.
The splitting of the one ZS when it got too big into smaller ones seems very interesting - how did it happen? what were the issues/problems/fallout?
(The questions of culture and life in the ZS has been on my mind lately.)
I agree. Rigid caste system - no chance for advancement out of your place, no chance for 'rocking the boat'. Probably severe punishments for doing so. I'd think there'd have to be some big 'pluses' for being part of the ZS or that culture to not cause rebellion (even if it's more propaganda, especially toward the end, than anything else).Nevertheless, they had to govern all that space for millenia somehow, and distributed uber-control is the only way I can think of it.
A Spartacus-like rebellion would be an interesting bit of ZS history. Imagine the players finding a world with the descendants of such a rebellion still living on - very Vilani at first glance, but (radically?) different culture. Pitcairn's World...

I agree.It also helps explain how the Terran Confed was able to topple it. It's already brittle and not communicating with itself.
And it also explains why the Rule of Man was unable to hold it together as it fell apart: they created one administrative capital.
Probably not - but I think if the Vilani play a large role in your TU, then it makes sense to have a good idea for what their culture was like. Kind of like having an adequate grasp of ancient Chinese history to understand some bases of the Chinese culture.In game terms, I don't suppose it matters very often.
Rob