Keep away from them. Use your speed and range to shoot until they get close and you initiate the charges. Then zoom away when the impending doom is about to happen. Also, try and get some DSers or Infiltrators so when he advances towards you, you can drop 1 or 2 squads of guys in the backfield he just left and because he is so slow he will not be able to go after your main army and the backfield guys you just dropped.
I have played 2 games thus far against 6 princes and 12 Blight Drones with Typhus and a bunch of Walkers and the strategy above worked well.