Note that Wikipedia claimed that the Russian guy may have been a double agent.
That would be a classic James Jesus Angleton chess move. If Angleton knew the Russian guy was a double agent then stick him close to Oswald so there is a nice trail leading straight to Moscow if Oswald became a patsy down the road for any future mission.
Angleton was both brilliant and crazy—made schemes that were ridiculously complex because he liked doing it.