They said in an interview that the Roman Empire reached its peak size-wise with Trajan even though the empire really reached its peak with Augustus. Unless I'm mistaken, I thought Hadrian added a few more territories and they only started pulling back afterwards.

Looking at the faction list, I'm guessing Cappadocia replaces Pontus. There's no reason to put two major factions right next to each other with that large a map unless they plan on giving us 20 major playable factions.