Well suppose that -175 str is -20% damage - a pretty reasonable estimate and far from trivial. That's less than 1/3 of the damage reduction of Forlorn Deeds alone. So slow stuff and find something else that is useful to do.
Even on Kunark raids I think their use is quite limited. Good luck landing on Trakanon without tash and malo, and if it takes you 3-4 casts (optimistic for a magic based spell on a L65 mob) the fight will be half over before you land it, so you're probably better off runing the tank. For the longer Velious fights it might make sense though. Of course, the Avatar of War has some seriously ludicrous stats.
http://mqemulator.net/npc.php?id=113457