And in highly belated response, shields function like armor. While you could wield them and give it the block technique, that’d preclude using a weapon. So far they mostly rely on the simple functions of using coverage to represent block chance, protection values for how much damage they absorb, and encumbrance as…well, how encumbering they are.
Even then, since they used the strapped layer, their encumbrance is tweaked with the assumption that most survivors still want a backpack.
And also, most of them only cover the hands, arms, and torso, which longer shields also covering the legs. I probably should make them protect the head though. Covering the eyes or mouth would be rather wonky though.