This seems like semantics, was it Putin that signed the order or did one of his henchmen? Don’t matter. This is the Nth novichok poisoning too. Putin is either complacent or participant.
> one of his henchmen
There are various clans of power in Russia, and not all of them are loyal, or report, to Putin.
Navalny had a lot of enemies.
> complacent
It's likely. The alternative could lead to some serious instability. For example, evidence suggests Kadyrov took out Nemtsov, but holding Kadyrov accountable could lead to chaos in Chechnya. Is it worth it? This is realpolitik.
Not saying that Putin didn't order it, just pointing out that the group of people with motive and means to do it is bigger than just him.