If agents have different utility functions / conative ambitions / "shoulds", they will presumably need to engage in some kind of negotiation in order to compromise their values and reach an efficient outcome. Presumably, ethical disputes can function as a way of reaching such outcomes - some accounts of ethics are quite clear in describing ethical reasoning as being very much about such a balancing of "right versus right". Even Kantian ethics can be seen in such terms, although what we woud call "rights" Kant would perhaps refer to as "principles of practical reason".