I don't think mages need ABS for most one on ones, but I can't see a mage taking on two people without it unless they're crap. And if those two people can lag it's probably a death sentence.

I can't see most low-prepped warriors taking on two decent enemies with much success, either (even a RBW has issues if the two people are decent), but at least the warrior can probably last long enough to flee if it gets ugly.

When you add ABS (from sleeks) to the equation, mages just become superheroes capable of doing things a melée class can only dream about. Having played melée types the last .. 8 or so years, I recently played an ABS Mage and I could not believe the sheer amount of power I had at my disposal and the kind of incredible feats I could pull off. And one on one, I don't see anything standing up to that power other than another ABS Mage or maybe a strong RBW that can retreat into the village without fear of you killing the giant. That was my main point above - you can't give mages unfettered access to that kind of raw power. At least the search for wands weeds some of them out.

So yeah, as long as the player is remotely aggressive, I think it's axiomatic that ABS = more deadly.