This mod is awesome (Ranks as best mod i've played so far.), I'm currently fighting for the Camulodian Empire. Currently i have a Castle and two villages for fiefs (Finally, a king a gives me the damn castle i fought for).
At the start, i fought for the Western Romans, believing they where the only ones with Roman units (Found out later that the Camulodian Empire where Romano-British). I stuck by the Imperial Magistrate guy for roughly 3 weeks, fighting against the Saxons. Every battle we went into, we'd have our asses handed to us, even when we outnumbered the Saxons. After many defeats and blood battles, i jumped ship and joined the Camulodians. Can't say that i regret it, the Western Romans have been beaten out of every castle they owned. Every offensive they launched failed. Several times they tried to retake one of their lost castles, but can never seem to win. Now All they have is Londinium, with some 600 or so troops sitting in the city.
Currently, the Saxons have the largest amount of land, followed by the Pictish Federation. The Camulodian Empire is beating the Camulodian Allies easily, since our Legionnaires that we have are awesome. I currently have 300 troops or so, 200 defending my castle, and another 100 or so following me. Just wish that King Arthur would declare war on the Kingdom of Cornwall. We can beat them, no problem, and with Cornwall's land in our Empire, we'd have control of South West Britain.