I like your idea Gandalf. I will ofcourse make my contribution to such a ladder and play some games myself, if you get it up and running
This 1v1 idea is specifically based on the MP part of the game and in this case 1v1 challenges. With timne and results a ladder of any sort will provide with informations on which nation has an advantage on other nations as well as which player is really good at 1v1. 1v1 is special because you don't rely on diplomacy but instead only on the nations at hand.