The Imperial reforms have no actual historical basis? I'm very confused.
No, the Lorica Segmentata (ie that stuff you see on hollywood legionaries) doesn't become widespread until after 14 AD, so it's out of EB's timeframe. The Imperial Reforms are 100% accurate, but some people think it's silly to include units that late in the game when they could chop them out and add more content to the early game. I say, why not move the end date back to about 50 BC if we're going to give such low priority to late-game units?