I agree with all of that.

As I argued in the piece, either Arya had to look like an idiot or Littlefinger had to look like an idiot, forced choice.

There were lots of reasons why it made sense for Littlefinger to take the fall (Patriarchy, Hubris because unchallenged for ever, Arya was trained to sniff out his kind of BS etc.).

The Tyrion thing was just baffling, Jon has always been an idiot (Ygritte really had him pegged from the get-go).