. . . They could sound too obvious or not a proper representation of real history but CIV series could not turn on a historical simulator.
Dog Knows, I'm as historically-minded as anyone on these forums, but in this I agree completely. I've 'played' Historical Simulations, and they were Not Fun.
On the other hand, if we don't get the historical basis right, we end up with strange things happening in the game. Here we are, I think, talking about Uniques for specific Civs (Rome, Persia, Early Modern Spain, etc) or types of Civs (Pastoral Aggressors) relating to their ability or inability to maintain a conquered Empire, and it pays to get the basis right, even if in game we are going to Abstract it almost completely for the sake of playability.
For example, making Rome an 'Amenity' based Civ has to be carefully handled, because the 'amenities' in this case was primarily the access to a huge Trade Network: Amber from the Baltic, Iron from the Balkans, Spices from India, Silk from the Han, etc. The Circuses part of Bread and Circuses never saved any Emperor who failed to provide the Bread part, and so Rome depopulated rapidly once the great grain trade from North Africa and Egypt was cut off.
And, of course, the Cultural side of Roman Amenities is all Borrowed: Gladiatorial games from the Etruscan funeral rites along with Hippodrome-like horse/chariot races, theatre from the Greeks (and Roman theatre, except for Plautus and company's Low Comedy, was pretty anemic compared to classical Greece's) - Rome's 'genius' was to take the original models from foreigners and massively expand their impact in scale, which could be (in game) related to their Engineering: nobody else tried to build race tracks or arenas on the sheer scale of size and numbers that Rome did, and some of the resulting architectural achievements were both Iconic and Singular.
If we're talking Septimius Severus, he was Punic on his mother's side and Latin on his father's, which isn't what most modern people would call black, i.e., Subsaharan African.
Or as Darius more colorfully put it, "A virgin could safely walk alone carrying a basket of gold from one end of my empire to the other. By the way, I'm very honest. Have I mentioned my honesty lately? I'm very honest. I certainly didn't usurp the throne because I'm very, very trustworthy." I may have paraphrased slightly, but it wouldn't be a Darius inscription if he didn't mention his honesty.
Thanks for the correction on Septimus: in fact, the Romans made a distinction between Black African and North African, using 'Aethiope' for the former and 'African' for the latter and not, as later Europeans frequently did, confusing the two (as I did!).
As for Darius, note that the same quote about the safety of gold and virgins was also attributed to Genghis Khan's Empire as an indication of safety within the state - or the stark terror inspired by the government's reaction to anyone breaking the peace. I don't think Darius' protestations of Honesty are any more fervent than the average modern politician's - or any more believable . . .