Wardens On The March

You have to kill 4 Warden groups. The 2 first aint that hard to kill, but then the 2 last groups IS VERY HARD TO KILL.
Some Ele Wardens use an AoE skill and of course your henchmens ball up, and die in less than 10sec.

How am i supposed to complete it? I have tried to do it, and so far it seems impossible with hench.

All right.. I completed it. Looks like the Domination hench really is worth taking with you.