Exactly my thoughts. I've never heard of the Parthian shot (that was a great read, thank you for the link), but I am reminded of the Battle of Austerlitz in which Napolean deftly executed just such a feinted retreat into ambush. Modern engagements are very different, of course, so I think the Parthian shot is an apt comparison to the grenade-carrying drones that are picking off individual Russian soldiers. In any case, you're right to point out that deception remains an important aspect of military strategy.