Remember that crumbling from combat resolution can work wonders on shrinking undead hordes fast. So just play the strengths to boost your resolution. Work the flanks, be sure you have a war banner. Sometimes it is better to keep your troops alive to keep getting combat resolution then it is to have a great first round. Once you are in combat with undead units you are there until they are gone so mark of Nurgle or hand weapon and shield with mark of Tzeentch giving you 5+ ward will keep you around dealing damage every round and make it difficult for him to gain more than rank bonus. Tzeentch sorcerer with lore of metal to deal with heavy cavalry and grave guard.