1. This is a result of EB's culture swapping. In the 1.2 patch, faction cultures are hardcoded so EB had to swap a few factions and cultures around. The Romans, for example, actually use the seleucid internal name (the game recognises them as being the Seleucids, though we see them as being the Romani). In the 1.5 patch, cultures are moddable and so the Romans will have their correct portraits and so on.

2. The team doesn't want historical personalities appearing in their mod. No Marius, Sulla, Caesar, etc. The retinue members seem to be an exception to this logic.