A weirdly written response on formspring:
http://www.formspring.me/JESawyer/q/416352235170066982
Q:
Would blunt damage dealing damage weapons have a weakness against light armor if they have an advantage over heavy type? Would enchanted weapons be able to bypass some damage-type weakness so as you should mix and match weapons but you can afford not to?
A:
The base damage of crushing weapons is lower than slashing weapons and has no inherent armor bypass (like piercing weapons), so they are less efficient against light and medium armor. Once armor hits a certain strength, the raw damage and armor negation values of slashing and piercing weapons can't make up for the high DT. Because crushing weapons have a higher minimum damage after DT is applied, they always maintain clear superiority in high DT situations.
An enchanted weapon will typically reinforce the basic properties of the weapon, not work around them. One thing we're trying to avoid are mathematical situations in which all obstacles can be turned into nails if your hammer is big enough. E.g., a mighty enough sword can eventually ignore the shortcomings of slashing weapons. Because piercing weapons' DT negation scales with damage bonuses and because crushing weapons' minimum DT is a multiplier of base damage, this should not generally occur.
However, the "bands" of applicability do grow as damage output rise. If everyone is doing 2x as much damage with their slashing, piercing, and crushing weapons, slashing weapons are dominant against higher DT than they are when they start out. Similarly, piercing weapons take over at a higher DT and hold that dominance for a larger band of DTs. Because there's no effective cap on DT, crushing weapons always have a place to shine assuming that some enemies will always have a DT that outstrips damage output.