Resonating Shield Damage Bug

I think there might be a bug with the damage output of Resonating Shield. I have a shield with 99 armor at the moment thanks to quality and an armor increase mod, which means Resonating Shield should be getting 6 x 6-8 additional damage, on top of the default 13-19 base damage, for a total of 49-67 damage.

My Mace Strike, meanwhile, does 153% of my mace's 13-20, which winds up being about 20-31. Each burst of Resonating Shield should, then, be doing over triple the damage of my Mace Strike, not even counting the armor break I'm inflicting.

And yet, I appear to need roughly the same amount of attacks from each skill to kill things. I'd even say that Resonating Shield does slightly less damage.

What's up with that?

Ah. Just noticed the Attack Damage multiplier of 38%. Well, that sucks.