Quoting: Playersoverpayed
It's all about the size difference. If NHL forward has 190lbs and NHL D-man has 220lbs, D-man will win 70% of puck battles and 90% of body-on-body battles. If heavier D-man uses his stick to create moment of inertia on lighter forward, forward has no chance. What he can do is just to learn how to fall down to reduce a chance of injury. In Connelly's case it was unfortunate he hit the pipe with his leg. But if you have 20 lbs less than opponent and you're going deep into a triangle with a goalie and D-man, you're asking for a trouble. It might be attractive, but it often cost you a lot.
If the dman can catch the forward...what happens when he cannot?
Skating is a much more important factor these days. If one is small and cannot move well, they're toast. If one is small and moves very well, they'll be fine.
This size-trumps-skill trope died a couple of decades ago.