Stamina based tanks were either inexistant or ineffective prior to 1.3.3 mainly because of resource management issues and secondly because of low damage. The latest patch addressed that with the changes to heavy armour but with every class skill based on magicka, all class skills are extremely weak compaired to a magicka build. My suggestion would be to make melee physical damage class skills scale off stamina if stamina is greater than magicka, or make them scale off stamina when a melee weapon is equipped.