I am not sure how the experience has been for you but I always have a lot of trouble in the vortex campaign as Teclis against the Skaven. Trying to break into Lustria is like trying to climb up Niagra falls with your bare hands.
I am repeatedly subjected to ambushes against my army by 3 or more stacks of skaven. Often battles are 4-5 to one and I get this over and over. Trying to take a settlement larger than 4 builidings I go up against anywhere from 6-10k Skaven. They seem to be able to produce full stack armies almost every turn from each of their settlements. It is outrageous.
As it is I can barely manage against them with all my attention. I shudder to think how they will be with the inevitable "DLC buff" they will get.