Should extend further still because Varangian guards are awesome & EB won't be complete without them

Or sans sarcasm:
The Lorica Segmenta was only starting to come in about the time that the game ends ie its something that was around during Emperial Rome.
EB is about the period which witnessed the rise of Republican Rome & the Parthians, rise & fall of Baktria and Pontus, Germanic expansion and the decline of the Helenistic states Carthage and Celtic societies. (unless you are playing as one of the latter in which case its about the rise of that faction & decline of the others...)