But you can hit while moving. 

• Equip power hammer/sword/axe 
• Ensure keys are bound to movement up/down/left/right
• Find Dreadnought 
• Move around Dreadnought with movement keys
• Click(don't hold) mouse on Dreadnought to attack while moving in circles around it

This is very effect against Dreadnoughts because they cannot use their melee attacks against you while you are behind them.  Also note that this doesn't work with the chain sword because of how it locks you in place. The movement keys are paramount to being able to do this and it feels very smooth. Though it clearly gives a big advantage to melee skills that can be used while moving,. Which makes weapons like Sword/shield more offensive than Great-sword, because  great-sword #4 cannot be cast while moving.

Please note that I like the way this combat works. One of the things I disliked about Diablo and many other ARPGs is that you get locked in place whenever you attack in melee. That is stupid when and enemy is fleeing and you have to stop to swing.