I saw the article to & warmed to the idea to some degree -
its obviously difficult for a club to employ some form of special team (or individual) for each eventuality - Throw in coach / Free kick attack / dead ball defend / restart / etc etc etc -
However, if someone were to maybe combine several of these specialist disciplines into one person (one salary) then it really starts to become more economically viable.

Its an interesting observation.

Ultimately for me:

Its a players responsibility to make sure they are warmed up properly, and mentally prepared to do the job and make an impact. The have had then benefit of watching on to spot areas that they can impact, and have the fresh legs to do it.

The bench is packed with various coaches, you often see them chatting to the subs and showing them tactical bits before the come on. So surely they are kinda doing it anyway.

But that aside there is definitely something about the negative side of being on the bench. Knowing you are only going to get a little bit of game time. I can imagine, that immediately after getting dropped you are keen to make a massive impact and prove the manager wrong....but after time I'm sure that passion dies.

Managers always talk about the importance of a squad, and keeping them all motivated. Which must be pretty tricky.