You can NOT balance classes based on raid buff/debuff situations. All dps classes should be balanced standalone, and any auras/debuffs gained through cross-class synergy should be looked at as bonus dmg. This is my opinion, you can't force people to be grouped with certain other classes just to be equal.

I am not horribly worried about this situation as I'm sure it will be remedied somehow, but as a 5boxer shaman and avid PVP addict I have a right to be concerned.