Honestly, all that tanks are behind the prot paladin simply because they have the same average mitigation as druids and warriors or the EH/mitigation of monks but they have huge amounts of personal, passive healing. The problem isn't warriors, it's paladins. With personal healing that high they should be taking more average damage to offset it. Basically if they were to remove SotR or reduce the potency of both SotR and SS, it would even them out with the mitigation of the other tanks. I'd go for reducing their potency so that they don't end up being spiky from that kind of change. SotR would fill in where the SS absorb had dropped.