While Erik was Marquis of Trinbar, he always spoke about himself as Margrave, just because it sounds better (and also to make him looks like better than another Marquis, even when the concept is almost the same between Marquis/Margrave). I had a pleasant surprise when the game changed it for Margrave within the new system. Also, he have many "unofficial titles" he gave himself along his way in Sirion. I think it can be done purely in RP ways.
We also tried to make a guild for an army, and that was a way of customization. It failed because of lack of interest from our players.
I will always prefer Second in Command instead of Vice Marshal...
