When I train people, I often duplicate exercises. That is, I set up X for one client, so other clients do X or a variation of X.
For example, I had three clients in a row recently. The first one did a rope pull/prowler push combination, heavy, for strength. Hand-over-hand rope pulls with the Econo Prowler, and the push it back. Repeat repeatedly.
The next client was also supposed to do the Prowler for conditioning. So as a change of pace - and because it was all set up - I had this client do the same exercise. I made it lighter and pushed a faster pace to get more of a conditioning effect.
The last client wasn't supposed to do the Prowler at all, but it was all set up . . . and that client needed to do a heavy leg exercise. So I took the rope off, hooked up a tow line to the Prowler, and added a pile of additional weight and had the client drag it.
None of this would have worked out this way if I hadn't had to set up the Econo Prowler and tie the rope on for the first client. All of them would have done something, but not all do the same thing with minor changes.
In every case, the exercise is fit into the appropriate spot and customized to the client. The load varies, the reps and rests vary, the exact usage varies. All are sufficient to get a training effect in the way the client most needs it. But rather than set up, say, heavy rows and then low-handle prowler pushes, and light prowler pushes for cardio, and a squat, I used the same tool. Lower setup time, each client hit a variation they don't see that often, and everyone got something out of it.
It's a time-saver for a trainer, but the primary consideration is still this: get the client the training effect the client needs, without risk or harm.