Soldiers in Britain speaking Greek

[I Am Herenow]

I just started a Casse campaign and, on my second or third turn, besieged the city to the north of my starting city and then they sallied out. During the battle, I noticed that one (or more) of the units were speaking Greek. The savegame is here.

[Ludens]

Maybe you heard the Eleutheroi general? Since Eleutheroi necessarily belong to one faction, they've probably been given the Greek voice mods for their commanders.

P.s. This kind of information is not stored in the save-game, it merely stores the state of the game world at this point.

[I Am Herenow]

Savegame is just before the battle IIRC, but you might be right about it being the General.