I agree with some of this, but it doesn't explain the lack of effort and this is sometimes where pressure acts don't really have any influence. Take Stringers 2nd goal for example, there was some awful play by Dow by the way when we had the ball, he dump kicked forward and Ridley intercepted. Cumbo wasn't on him at this point, but it was a mark on the move and he wouldn't have been able to influence it, so no problems here. Ridley kicks to McGrath and Cumbo stands the mark, ball gets kicked back to Mackay, Cumbo watches McGrath run away from him, ball goes to Ridley, Cumbo sprints to put pressure on the kick (pressure act would be recorded but had no influence on the kick), Ridley runs away from Cumbo who we now see jogging behind him, Ridley gets the ball back and kicks the ball long down the line which Nank misses the punch and then Gresham feeds Stringer.
That was the type of pressure that I saw at the ground and that goal stuck in my mind from the start, watching a "pressure act" that had no influence but then not doing the secondary chasing. I know you love to bag out Mansell, but I know he would have influenced those contests in a more meaningful way.
Personally I think Cumbo thinks he's a 40-50 goal forward and plays like it defensively, when he's only that in theory.
BTW when I say compete with Ridley in the air, I was expecting him to hold his ground in front (and thats all I've said, was to hold front ground, but he was caught out the back way too easily). Ridley took easy marks especially in the 2nd half, because he didn't hold front position. Not saying he can outmark him, but you want him to compete, try and bring it to ground, and if you don't then at least you are goal side to set up the defensive press.