It seems that Eidolon of the Blind has aided our cause. We have both arrived at the enemies capital without them preparing.
http://www.dom3minions.com/~gandalf/CoE3/AAR2/b3.JPG
And thank he-who-must-not-be-named but I also have saved up enough sacrifices to make a Call of the Deep summoning. I was blessed by 3 Shamblers coming up out of the depths to join our army just in time for the fight.
http://www.dom3minions.com/~gandalf/CoE3/AAR2/s1.JPG
Even though they have a slightly defensive position I have no concerns for the battle now. Zag'mi and I shall both attack from opposite sides at the same time.