Well Liam Neeson being white was explicitly part of the story and a play a play on blatant racial stereotypes, he had an asian stand in who "looked like" ras al ghul would so he could hide his identity. In fact because it's a rather "realistic" take on the superhero it's implied that Ras Al Ghul is not a single person, it's always just a cover for the current leader of the league of shadows or whatever they are called