I had some success with magma totems in a clover pattern around the sapped toon, but that is somewhat dependent on how smart the rogue is (he can sap one of the other shaman moving out to drop totems). TBH, I never did find a 100% solution to it. The best thing I ever figured out was to leave 1 toon behind until it dies, which really isn't much a solution because you know that rogue will be looking for you from then on for sure.