I don't think we really know all that much specific about how Intergang operated, so you'd be pretty safe creating them in whatever form you need. We know there are operations around the country/world and that Bill Church, Sr., ran it in S2, using CostMart (presumably a take-off on WalMart) as his legitimate cover business. My feeling was that Intergang wasn't as centralized -- or maybe as ruthless -- as Lex Luthor's crime syndicate, mainly because Bill Church didn't seem to have the ego (and probably the vision) that Lex did. He was able to delegate more and didn't seem to have to be involved in every decision, the way Lex seemed to delight in being.
As for how it compared to other "real world" crime organizations, I have no idea ... they never did a direct comparison, or even gave that many details, and I don't know enough about those real world entities you named to be able to say. But I do think it's safe to say that both Intergang and LexCorp were loosely based on those organizations and you'd be fine to pull out details that interest you when fleshing them out in a story.
Kathy
