The Perils of Osmosis

I'm reading the Lord of the Rings again at the moment. I used to read it almost every year for a while there, but it's been close to ten years now so I thought it was well time for another foray into Middle Earth. Last night I was reading the Two Towers and I came to the bit where Aragorn, Legolas and Gimli meet Eomer on the plains of Rohan, and I noticed that Eomer refers to himself as "Third Marshal". And it really struck me, because in my own books (and I hesitate to mention them in the sa...