Yeah, counters just don't cut it in this meta.
So far a lot of people tend to ignore the Whisperer until it spawns a copy or two. On first playing it, most people are hesitant to use a removal card on a 3 point bronze. It doesn't take long to realize that Whisperer has a theoretical 27 maximum value, though... Worst case, it is good lock/removal bait.
The Sorceresses tend to draw a lot of immediate removal if you don't buff them to 6+. The stratagem, Vrihedd Sabateur, or any of the ST "buff a unit in your hand each turn" units help set them up, though. I even tried a few games using Invigorate as my leader, but a spell heavy deck usually meant I was wasting at least 1 point of buffs per charge...