That's neither necessary or sufficient! Notice that they could be bilaterally symmetric and two arms/hands positioned vertically on their front (anterior?) so n

That's neither necessary or sufficient! Notice that they could be bilaterally symmetric and two arms/hands positioned vertically on their front (anterior?) so no left/right hand distinction (but top/bottom instead) or; they could be asymmetric but have two hands/arms on one side, and one on the other, still giving them a left/right side choice.