I suppose it would be efficient if one person produced a satisfactory conclusion and the other one didn't. From the point of view of the voter, it's efficient if you get the best outcome. Maybe if all MPs were as efficient as the best one, then the voter wouldn't have needed to go to all of them.
Many, of course, still just go to their local person, the one they might have known, the one they vote for, the one in their area, but certainly there is duplication of effort.
I would say that judged against the general inefficiencies in our political, economic, and social system, those are pretty minor.