Sorry, that's partly me misreading the original question. As for the Mafia, I don't know entirely from a lore perspective? I know that again, stereotypically, orks are prejudiced against by law enforcement, and most of them have a record before they reach the age of 18, so it probably isn't too far fetched to assume they are a part of organized crime? At least, not any more than any other metatype, I would imagine.

And if we really want to play to stereotypes, who better for the mafia than a group of metahumans who really, really appreciate their mothers?