This is the sticky point that tends to make me uncomfortable in fandom rp's tbh. Like, I always feel beholden to follow the canon somewhat, which feels restricting. I know it isn't necessarily a requirement to follow the canon, but the niggling idea that I must is just... there, regardless.
Vitellius was one of the four-Emperors if I recall right. Was his contribution to future rebellions because he was an early abuser of military coups in the Imperial era, or did he do something else? Because surely he wasn't Emperor very long...