You have zero reason to believe that rando muscle within a Russia mob family has "elite training."

This is the less important aspect of my argument. John Wick is in some ways more realistic and some ways less realistic than Die Hard however they are both entirely impossible or at the very least incredibly unlikely. Arguing that a movie is "more impossible" is like arguing that a sandwich is "more perfect." It's an on/off switch its either true or untrue. A scale of impossibility is silly.