I think that there is no possibility to achieve such submission from some factions as the roman or the egyptians because they will never accept it.
Or is it easier to achieve an enemy faction to become a protectorate if there isn't a great cultural difference? For example between gauls and britons, greeks and macedons, pontus and armenia ...I noticed that it happens more often amongst theese AI controlled factions.
I would like to know your opinion about this issue.
