Interesting observation. A few of those Russians may not even be ethnic Jews. I've a friend who teaches immigrants in NY. Mainly Chinese, with many Russian Jews, and a few Latinos and Haitians.
My friend was surprised to learn that one of his Russian students was a gentile (they're that rare). The student confessed that he pretended to be Jewish, because it easier to immigrate that way. (The US extends "refugee status" to Jews, Baptists, and Jehovah's Witnesses, so there's no waiting list, and they immeadiately qualify for SSI and food stamps -- a relic policy leftoever from the Cold War).
I wonder how many Russians pretend to be Jewish to get into the US or Israel?
Immigrants from all nations claim to be persecuted, whether true or not, to get into Europe and the US. Immigration policy throughout the world is messy and corrupt.
It is estimated that 60-70% of Russians emigrating to Israel are non-Jewish. They are not even Jewish according to "Hitler" since they claim bogus "Jewish" relatives. Nevertheless they are allowed to come in because Labor and Meretz need more seculars to oppose those Orthodox riffraff who reproduce almost as fast as the Arabs.