... I don't know if my research skills are letting me down, but I'm really lacking in detail on job roles in the second century. I tried rummaging about Tribunes previously, and now about centurions, and although there's more on centurions than tribunes, it mostly seems to be Earlier, Much Later, or at best Far Away. So I'm thinking exceptions should definitely be allowed. Even if grand-daddy Centurion did it THIS way in Egypt, surely that is no reason for his grandson in Britain to have to behave just the same!