Lady Deathwhisper and RetributionFollow

Looking at different raid comps for Deathwhisper (10man) and the question came up -

I know that Mutilate Rogues can still deal ~passable damage (not great, but maybe 30-40% of normal dmg as opposed to 1%) to the Reanimated Fanatics (99% immune to physical dmg) because of poisons and Envenom.

The question is: can Ret paladins do the same? Or does the decreased physical damage kill damage too much?

Figured I'd fire it out to the experts. :)

The reason I specifically asked is because I'm putting together a partial PUG for ICC10 tomorrow, and the two DPS I know I have are two (very good) Hunters. Obviously, I could load the raid with a couple of ranged magic dmg dealers, but I have a soft spot in my heart for melee and want to be able to justify bringing a few melee PUGs in if they're good players. We just need enough magic dmg to get the adds down and I wanted to know if I could count on some damage from Ret if we're overall shy on magic dmg.

I was specifically wondering if seal damage got neutered along with their physical dmg, or if seal dmg is calculated before the 99% physical damage reduction.