ive boiled it down to what i think will happen
blood: mark of blood, self heal, seems like it tanks a single target, that deals phys damage, very well
frost: unbreakable armor, howling blast, good passives.... i think this build works best for being viable to do it all, single or aoe, phys or magic
unholy: bone shield, tons of aoe stuff, aoe (aka 5 man) tanking seems to work well here, as well as vs magic damage (even though EJ is mentioning good unholy tank builds cant afford AMZ, so im thinkin just good for the aoe threat)
just my opinion though