I played the diplomacy mod for a few months and I think most of the changes made are realistic and faciliate the gameplay a lot.
For example to send recruiters from your castle to the villages who recruit up to 50 recruits from the villages for you. You have to pay the same as if you go to the villages yourself, but it saves you a lot of time. Of course the recruiter with his recruits can be attacked by bandits or whoever you are at war with, and then your money and the recruits are lost, if they get annihilate in battle.
I think this is realistic and even if it is not planned to include the diplomacy mod into europe 1200, some of the features should, primarily to make europe 1200 also playable for unexperienced players and players with limited time to play. It is very annoying to run from village to village and spend hours of playtime just to recruit 0- 15 recruits from every village and that after every great battle just to replace your own casualties.
Just a suggestion, of course.