It does apply at scale. If one company were to “hire [another] company to ship a package”, there would be no question that the delivery company would be liable

It does apply at scale. If one company were to “hire [another] company to ship a package”, there would be no question that the delivery company would be liable if their driver did something negligent. If they meddled in the delivery company’s affairs, specified almost every aspect of their operations, entered into a sole-source agreement that forbids the delivery company from working for other customers, then that is an entirely different matter.