It's not like the choices are between a 'lively' cheating AI that can't play worth a fiddle without massive cheat bonuses, and a soulless unbeatable superhuman AI that plays fair.
If it were possible to create a superhuman fair playing AI then the Civ bonuses themselves would create personality (in fact often strongly related to the desired personality characteristics of each civ!) even without additional 'hard coded' imperatives, which would of course also be possible.
And in this scenario create a compelling weaker AI would be much easier than trying to create a compelling strong AI (from a very weak base). There will need to be some 'move' evaluator function and simply picking weaker 'moves' would so fine. If that creates uncompelling AI then we could get back to cheating and impose resource penalties, but with much more compelling play. E.g. - kind of like playing a strong chess engine with knight odds.
If it were possible to create a superhuman fair playing AI then the Civ bonuses themselves would create personality (in fact often strongly related to the desired personality characteristics of each civ!) even without additional 'hard coded' imperatives, which would of course also be possible.
And in this scenario create a compelling weaker AI would be much easier than trying to create a compelling strong AI (from a very weak base). There will need to be some 'move' evaluator function and simply picking weaker 'moves' would so fine. If that creates uncompelling AI then we could get back to cheating and impose resource penalties, but with much more compelling play. E.g. - kind of like playing a strong chess engine with knight odds.