I'm not sure what a role problem is, but a hybrid defender/controller would be half defender and half controller... not too different from classes that have a strong secondary role. When the fighter/wizard is in melee, it is marking opponents and being defender-y. When the character is not in melee, it is blasting opponents with spells and controlling the battlefield. A downside to the fighter/wizard combo is (IMO) that you pretty much have to blow your Hybrid talent on fighter armor proficiency, or get killed in melee. Then you need some way to cast your wizard spells through your weapon, or carry around a separate implement.Wouldn't a hybrid have role problems? I have to confess that I don't have PHB3 (though I do have DDI), and so have not read up on the hybrid rules.