Playing civilization with Scientific and Philosophical traits would entitle as "King or Queen of Science"(Martin Prince or Lisa Simpson wannabe) just as Babylon traits from Civ3 contribute as "King of Culture"
BTW, Koreans' UU, Hwacha would probably replace a seige unit between the catapult and cannon, while Ottoman Sipahi probably classify as anti-gunpowder cavalry unit.
You know, there should be at least one or two civ leaders who would possess unique air or navy unit.