My 'pologies, Kalih. I must've missed that. However, notice that, at the very least, 4x shaman 1x tank is not mentioned in either pve or pvp.

Furthermore, I haven't seen any 5x shaman pvp videos besides the one that was taken by a player in an AV match that happened to be grouped with Xbox (and arguably, at the time, AV was a PvE encounter). 4x shaman + another person playing healer seems to be the big PvP build.