For my last villager, I found that once the % of DB got high, 90-100 it seemed to fire a whole lot more than when at lower %'s. It could be just perception or RNG though. I do wish that when I landed a DB on a charge or pugil, etc, that it hit harder than the DB in normal rounds of combat because staff, spear, and polearms are typically lower damage output weapons due to the lack of dual wield.