Not to derail this thread before it gets started, but I think that Korea may not be the best civ to examine this with. It's true that the per-specialist boost benefits empires with more specialist slots, but Korea doesn't have any infrastructure bonuses and is also an amazing Tradition civ. I think Liberty is more likely to be seriously competitive with civs that don't necessarily have great bonuses for Tradition. The main characteristic I would look for is some kind of per-city bonus that kicks in early and enables a quick faith- or gold-based snowball.
Civs that stand out as good candidates to me are Shoshone, Maya, Ethiopia, Celts, Egypt, Russia, China, Arabia. And then maybe Netherlands, Songhai, Siam, Indonesia.