That's why three groups have been allowed in Gallia so far. Because they were nice enough to ask.
Plus, Gallia is extremely hostile to anyone coming in and disrespecting the supreme dictator of the lands. I mean, it's the difference of someone knocking on your door and asking for a cup of tea while they explain a deal they have for you and someone barging in with dirty shoes, while house rules clearly say you should take your shoes off before entering the household.
