I would have ruled on the column pursuit differently in this one... I would have expected the group contacted to confirm, as the contacting group couldn't, or they fight at -1, and both of the pursuing Wb in column would have stayed together.
Been re-watching some of the videos and one of the tips that I've picked up is that you don't need to be side by side with another friendly element in order to stop an enemy from closing the door. You only need to be close enough so that an enemy 'door closer' would stray into your TZ. I haven't done the geometry but I suspect that you can be up to 80mm away from the front corner of the friend you want to support. Thanks to Tony, Mitch and Luke for that.