Yeah, it is excessive in a way. I was really pushing for Warchanter Frozen Fury to get a DC similar to Stunning Fist, on the reasoning that Bards could never splash Monk and get it directly. But even that one I didn't want to benefit from Stunning items...
So the devs do that, make it better with Stunning items, then need to fill in a t5 slot so they produce an AOE version too! And Bards already had at least two ways to cause AOE helplessness...
Perhaps it would be better if Spinning Ice caused Slow on the enemies (like what happens to players who stand near a White Dragon)
PS. Knowing that Warchanter is supposedly the "worst enhancement tree of all" may make people less likely to point out when changes are too strong?