I have my own personal theory that the celtic units will be unlocked with a dlc about Arthur. It would be like a Med 2 Britannia campaign 2.0. Why not? we already have the Vikings raiding 300 years before there were vikings, why not have a DLC with King Arthur and the Knights of the round table? I wonder if there may be legal problems though with that other Arthur game thats practically a total war knockoff.
Im calling it though. this game's CIG will be AIB.
factions:
Romano-Brtitish
Caledonians
Northmen
Picts
Ebdani
Saxons
Cymry
Amorica
historical battles:
Battle of mount Badon
and of course since CA and just 'bout every proper englishmen a fan of Monty Python
and of course it'll unlock two handed units too: