I think weapons such as clubs, hatchets and troika-like should have a different damage type. Piercing definitely wouldn't work. Shadow, no. Elemental? Not really. Not really normal either.

So I propose a new damage type: Brute.

Brute damage would be used by weapons such as the one listed above. It'd be used by heavy weapons, large ones, with blunter blades. Few guns would use it. Same with bombs. Brute would be aligned with monster types like this:

Beasts: Weak to Brute
Construct: Resistant to Brute
Fiend: Neutral to Brute
Gremlin: Weak to Brute
Slime: Resistant to Brute
Undead: Neutral to Brute

Brute damage weapons would involve slow, heavy swings that have potential to deal great damage. Many would also have a chance of causing Stun. For example:

Brute Smasher
5.3 bars Brute
2.1 bars speed
Moderate chance of causing Strong Stun
A heavy weapon capable of smashing monsters flat.
2*

A heavy hitting weapon with huge damage for a 2*, but only one hit combo. A swing like the Troika charge attack:

O (Heavy smash)
| (Slight move forward)
* (Player)