Tbh I've been doing this for awhile now with different artifacts. And yes; you are right certain combinations are bordering on OP status but let's be truthful in this case it's likely the issue is more the fact that precision needs to be looked at more than anything else. I've been dps'ing in support role with nearly all power sets. I doubt your friend would have been as successful if he was might based. I've experimented with both might and precision spec'd while in support role. Precision is much easier to pull off and numbers wise much much bigger when it comes to the boards.