Panzerkin (has it worked for any of you)

So I find tanking with one of my druids in bear form an impossible way to hold aggro off my other three boomkins (level 38) in multi-pulls.

Has anyone played with a panzerkin build? (tanking moonkin) Just for pre-BC instances. I have the theory that if I pick up a healer this could work pretty well just off the other moonkin being specced for reduced threat and my "panzerkin" not being so (Also panzerkin doing wraths rather htan starfire, because of knockbacks). Also panzerkin dotting more than the others.