I thought that Cain should not be doing damage while on combat, as you can see his base kit offers no damage to heroes. I supposed that some players may want a bit of damage to compensate for uncorditaned teams on QM, all followers are supossed to have the same dps. Another concept for that heroic, was to summon a random (non present) hero of the game (except cho'gall) to help him, but that was too exagerated and out-fantasy. Anyway, I agree with you that summoning is not usually a support...