MiniFig, I think you have some concepts about the hybrid class a little mixed up. Your class is hybrid and a hybrid is two classes equally conjoined together. There's no primary class and one will never truly outweigh the other, as you will have to alternate between the two class's powers. There are several rules that go with the class as detailed in the PHB3. For instance, the hybrid class only gets the armor proficiencies of its parent class if both parent classes are proficient in the same type of armor. In this case, the shaman class does not have shield proficiency (light or heavy) so when joined with a class that does have it, it will be lost as they do no "match up" so to speak.
At any time in your career you can take the Hybrid Talent feat, which will allow you to choose one aspect of the parent classes to utilize. There is a special paragon path that will allow you to take that feat a second time.