Either Rhitantyn and Grynewaht are related or Aervina is just a really common surname for Garlean roegadyns. Which I guess would make sense considering it's just latin for "fat."

You gotta wonder if it's just a result of them being assimilated into Garlean culture that caused them to drop the whole thing where their surnames come from their dads with -syn or -wyn at the end and making their surnames into more family names. They at least keep the cool Aerslanti names.