You'll never know with certainty, but you can certainly know more than you do now. But you won't if you don't pursue the truth, and it becomes a self fulfilling prophecy. As I said in another post, maybe it's possible to sequence DNA of the emperor or a collection of contemporary subjects, determine an approximate ethnic makeup, and revise the images based on that.
Or, we can just assume we are already correct because we'll never know anyway.
