C352 Duke Hamilton!
Perhaps, when the three of them met, Duke of the North and Duke of the South would say to Hamilton, "The reason why you were conferred the title of Duke of the Single Emblem is because your ability is only at the level of the Duke of the Single Emblem. On the other hand, we are conferred the title of Duke of the Double Emblem because the highest rank in Foploarus is the Duke of the Double Emblem