Ignore def doesn't stack

Something still isn't stacking.
It's very minuscule though
Range:
56980-81400
Using phantom blow(105% damage 20% pdr)
30% PDR codex, 15% PDR dagger, 20% PDR skill 5% ambition
6% total damage from katara, 25% PDR mob
Numbers:
(((81400)*1.05)*((0.75+(0.25*0.7)))*1.06=83803
(((56940)*1.05)*((0.75+(0.25*0.7)))*1.06=58621
Phantom blow damage should be 58621-83803

As you can see, I hit a 575xx hit.
Can anyone confirm whether stronghold mobs are 25%?
If they're actually 30%, then I'll feel really stupid.

they are actually 35%