You talk about all these invisible NHL defencemen who actually engage physically with their opponent in a prime scoring area. Can you actually give us examples and put faces to these NHL dmen, because what I usually see with the smart #1 dmen like Vlasic, Keith and Doughty are active sticks and the high hockey iq to get into shooting lanes to prevent scoring opportunities. Physicality usually comes when the puck is along the boards or when trying to clear the front of the net, not in a prime scoring area where all the player has to do is shoot to get a dangerous shot on net.
By "engage physically" I don't just mean hitting, I mean getting in close to the player and actually engaging them. That includes an active stick and positioning, but you have to actually engage the player and not stand there and let them skate around you. If you can flatten them great, but at the very least you need to engage your man and make sure he can't step around you into a better lane. Dunn failed at all of the above and got caught out of the lane and exposed, and that isn't a knock on him as a prospect as most junior defensemen are behind forwards in developing pro level defense.
Here's Keith defending a 2-on-1, he engages Lucic and takes away his time and space as soon as he gets some support.
Here's an entire video of Lidstrom. There are a couple 2-on-1s where he doesn't step up and protects the lane, but he always stays close enough to be engaged.
Here's Vlasic using positioning and his stick to force Duchene into a position where he can engage him and take the puck.
That's just a couple examples. It's so much harder to find highlights of solid, steady defensive play than goals.