Loki and Hermes are well-known gods of thievery.
As for saints, St. Nicolas is the patron of thieves.
As for clans, often there was some community of people that had any normal work forbidden by the society or some inner rules. Some opressed small nation could choose non-collaboration policy and crime remained their only way of living. Gipsies or something similar. So the clan often appeared as a ready thing, from the start, you are right here, IMHO.
Crime was always very well organized. The head thief in the late 18 cent. in Moscow became even the head of the police. Pirates in Rome times terrorized all the empire and had even their state. in Kilikia. (Also they had a state 1500 years later in Madagascar).
When a state is doing some its function badly, some crime organization will always appear to cover the function. And as our states are organized poorly mostly, the result is obvious.
Please, correct the question. The header and the body ask for different things.