He pretty much killed all of the Jewish Bolsheviks before the war. His anti-semitism was lifelong and well-documented. He just was more subtle than Hitler about it.
I think he killed them because they were Bolsheviks and rivals and Jewishness was a little factor if any. Soviet administration was still heavily Jewish until 1970s when Brezhnev allowed emigration.
“The Allies could have waltzed in there at a fraction of the cost, but the Russians insisted on taking the city themselves.”
The Russians didn’t insist on it, in fact the russian people had no say in the decision whatsoever. The only person whose decision mattered wasn’t even Russian at all — Stalin