It’s not beneficial for everybody.
I said two different things:
- For some people, in some phases, it can be a good idea to do the isolation/assistance work first and finish with your “main” lift. Paul Carter also wrote about that. This is mostly for people who are super strong and training specifically for muscle growth. This allows them to get the most from the big lift without having to load it super heavy.
Another instance where the approach can be used is if you want to fix a lagging muscle group. For example, if your triceps are dominant in your bench press and your chest is lagging, you can do two things: A) train the heck out of the triceps before bench pressing, you make them weaker because of fatigue and the body must use the pectorals more, improve your capacity to recruit them in that exercise or B) do light, non-fatiguing, work for the pectorals to create peripheral activation which will improve your capacity to contract them, then do to the bench with “awake” pecs.
- Doing explosive work at the end (or close to the end) of a workout. This work only with people who are VERY explosive and only on execises where you must stop the weight at the end to avoid joint shock. Like a bench press or a squat for example. What happens is that in those movements, if you lift explosively, you must decelerate the bar to stop it before your joints lock up. Going to the lockout at full speed could be damaging for the joint so the body instinctively decelerate to avoid the shock. The more explosive you are, the sooner you must decelerate. A very explosive person might actually produce less max velocity by doing those movements fresh because they decelerate super soon in the range of motion. If they get some fatigue, they can’t produce as much initial acceleration and thus will decelerate later, reaching a higher max velocity.
This wouldn’t apply to the high pull, olympic lifts, jumps, throws and sprints. Because in these movements you do not voluntarily decelerate the weight because there is no need to stop it. It is “projected”.
One caveat: on high pulls with very light weights it can apply because with weights that are lighter than normal training weights you will have to stop the bar because it will move up to fast that it can reach a position much higher than the normal finish position.
So you could do it with high pulls with very light weights. But personally I don’t really see the point.