the factions of the mod currently are
1.Rome
2.Parthia
3.Carthage
4.marcomanni
5.the Caledonii tribe
these are the nations i know about that were in the time of trajan and im going to reseacrh more about them and im not sure yet if there will be new units but im gonna try. and id like 2 see at least 4 german tribes and 2 tribes in the britain scotland ireland area and a few more in the east.