A heavy attack is "charged" and if the strike lands on a target that is blocking it will render you unbalanced and stagger you. Does this apply to wrecking blow?

I have a feeling it doesn't as I was in PvP with my DK tank the other day and I was blocking WB and the player just seemed able to keep spamming it until my stamina was drained it was all over, while if he had been heavy attacking he would have been staggered. WB SHOULD stagger the player if used on a blocking target, and as an NB player I can also say that Surprise Attack should maybe also stagger you as it's a very powerful attack that is visually forceful, at least if the blocking is done with a shield.

Come to think of it, a lot of skills should set the player off balance and stagger them if used on a target blocking with a shield. If anything, heavy attack should not stagger you considering how weak it is compared most skills and when those skills doesn't stagger you.

Am I making sense?