I have no clue what kinda defenses that Night Widows have going for them, but lemme tell you something. I fight them at level 35+, I can fight an even con Night Widow and she'll dodge my Rain of Fire. I'm one of those crazy people who slots RoF for accuracy as well (I want all of RoF to hit for better scourge.) So we're talking something like 130% accuracy on a 'pet' that can't be debuffed by the Smoke Grenade they like to use. I've had them dodge all but 2-3 ticks of the power.
*That's* just wrong.
--Suichiro