I think you should continue with the tank strategy, but be ready to get FMs should the need arise. The undead or in fact any race or player seem to suffer if they are forced to make too many choices and can't find a way to cut them out of the situation. Cause as you and I know, there is more than one way to win the battle besides micro. As for knights dying too fast, they are only useful as better footman you can say - minus the effects of Defend. Even with 5-11 armor, they still fall like flies because of thier low HP count and no special ability to make them worthwhile. Like with Aboms, you can eat corpses to heal them and rob enemies of regeneration powers. Or bears you can switch them out and cast rejuv and go abck into the heart of battle. Tauren have thier pulverize which can waste units quite effectively. The only reason knights were needed is so you can use Normal damage against CF mediums, and they would have to get by them to web the Grys. And Grys have magic damage which destroys aboms and stats and does a chunk of damage to low HP heroes like the Lich.