I understand why you might ask that question, SSA, but it turns out that there's less to this than meets the eye. Russian Mafia got plenty of headlines here in the US, but a story in the NYTimes a few months ago said they were smaller and less effective than first thought. They're big in Russia and some other countries, not so big here. Mostly they shake down Russian immigrants here. They were involved with the Mafia in a gasoline tax scheme, in which they collected excise taxes on gasoline but never paid it. It was a big, sophisticated racket but the government caught on and busted it.
It's not new that the Mafia "lets" others into rackets. The Mafia has simply abandoned many neighborhoods to other ethnic gangsters, or has found the going too tough (or visible) to continue. In NYC, Asian and Jamaican gangs now dominate much of the drug business, and street-level gambling goes to whoever prevails in neighborhoods.