The relationship between sch and whm is synergetic, but sch is more of a hybrid class and whm is more of a pure healer. The sch has it's summon, but that is nothing more than a supplemental heal, the sch however has more freedom to dps because of it. I think some players who play whm but have never played sch, or have friends who play sch, may assume that the sch role is the same as whm, and should be doing the same things. That is their mistake. Then again, there are some sch who, when the whm starts having troubles, they do not pick up the healing to help out. So there is a story on both sides.