Not always. The higher seniority guy knows what he's doing. Take my clerks for example. I have one that is pretty green. He can do it all by himself, but he's still slow. If I'm in a pinch and need to send him a clerk home I'm sending him home because my high seniority guy can do the job twice as fast. In the long run I'm breaking even or better because he's doing it in half the time and not getting that much more pay.
For the record I've never been told to get anybody off the clock because they make too much. It's because I'm not going to make my numbers