I never saw any of Aikinars stuff but it sounds good. I always thought this issue was a stumbling block in immersion. For Rohan especially it'd be great if you could really set up the 'Marshall' system, you know 'first marshall of the riddermark' etc etc that would be really cool.
I like to grant each section of the family tree (from the second generation) special family land dynasties, to keep a feudal feel going. For example in my HE campaign I sent 2 3rd generation fellas and their sons in an armada to assist gondor. One of the groups I had take Osgiliath & Cair Andros, and the Other took Umbar and surroundings. Now if that line could become 'Idhron Lord of Umbar' that would be awesome, or the other would be 'Daeron Warden of Cair Andros'. I like this very much
