If you was going to make a dodge tank then rogues are much better. Not that any class can hold aggro exept maybe for a kiting hunter. tanks dont work anymore vs anything stronger than hogger.
now you need a bunch of high dodge melee twinks, rogues preferred, to switch aggro between so that their hp wont drop faster than they can heal with bandage, lifeblood and lifesteal. this is because mobs thats higher lvl than you get increased dodge,miss and parry. parry their chanse to parry scales absurd and will go through the roof as lvl increases. even hogger got over 35% parry so it wont take many more lvls to get 100% avoidance for mobs if you attack in front of it. the dpsers will attack from behind, wont get parried and take aggro.
holding aggro when in front of a mob is impossible.
even if it was possible, there would be no gain from having a single tank when all heals got long CDs. the tank would die with all heals on CD and cause a wipe.