For medieval civilizations with population goals (Poland and Khmer immediately come to mind, there might be others as well), does one simply have to hope that the plague doesn't arrive, and reload if it does?
To be fair, imagine the disgust a player of regular Civ can feel when he sees that!Certain barbarians can spawn inside cultural borders. This is so that you cannot prevent historical invasions by covering their spawn region with your culture.
That's more a consequence of the numbers involved I'd say.In fact, playing Babylon other then UHV or OCC would bring even the most accepting roleplayer to tears.