Crush should be balanced in two ways, with the second being the most important.
1. Crush weapons are shorter than all other weapons, meaning a crush weapon will only get first strike against a competent player if it's an ambush or by working in concert with teammates.
2. Crush weapons are slower than all other weapons, meaning a player with a crush weapon attempting to strike can be "spammed" through. They will never have time to strike a player who constantly attacks with a reasonably fast weapon.
This puts crush weapons in their proper place as utility weapons, useful only when combined with teamwork, ambushing around corners (particularly useful to hold towers on siege maps) or against someone who has made a mistake.
The bar mace with crush is broken because it is effectively longer than many (all non-sword) one-handed weapons, giving it first strike in many match ups against shields, and it is far too fast to be spammed through. No matter what weapon you are using, 1H, 2H, polearm, assuming you play perfectly against a bar mace that also plays perfectly, you will always lose. Assuming two players with bar maces play perfectly against one another, the winner will be determined by random chance.
Many people say the correct response to crush is to dodge the attack. Dodging relies on failure in this case, not success, and so it cannot ever be considered as a proper response in game balance. (Dodging is only a correct response in ranged combat when you are at such a distance that you have time to move out of the way no matter where the arrow was aimed. In all other cases the correct response to ranged weapons is a shield.)
