Still, three shamans does not "stack a raid" and become super imba. Totems affecting the entire raid are not in the patch notes, so either they do affect the raid and I'll have one or two totems per shaman to drop (lost efficacy) or my shamans would likely be spread amongst separate parties to give totems to more people. I'm not seeing them as the best bet regardless of if/how they stack and how many people they benefit.

You'll also want at least one resto shaman. Lets be realistic. This isn't a raid of boxers. This is me plus a lot of single player characters. Four shamans in said raid? That is shaman heavy now, even considering their healing OPness.