What I realy liked is fighting against the barberian more than fighting with them!!!!!!!!!
you have to be prepaired for many other factions to attack you especialy the Vandals and the Huns when they come with thier massive hordes.
But I liked playing with the Western Roman Empire more because it was a hard challenge and I had to face alot of barberians all by myself. But what I didnt realy like is about the horde armies which are full of missile units mainly horse archers they kill the excitement of battles butI managed that by two things. First, most of the battles i played with those armies were inside cities so I will not be harrased by lots of horse archers. Second, I deafeted the Huns (the kings of archers) by assassinating and killing thier family members to the last one.