Does it not occur to you that you could be making massive assumptions about Harry's physical state that none of us actually has any inside track on? What you are saying now is pretty much the identical narrative that was being spouted ad nauseum by all and sundry this time last year, yet despite his presumed fatigued, jaded state he still went on to become top PL scorer.
So how do you explain that?
Yes , of course it is one POSSIBILITY that Harry is suffering from fatigue, and it's also posible that he could do with a break, but that's just one of several possible explanantions. It's equally just as possible that pure and simple he's struggling with a run of poor form atm, that he will work through it just like he did last season.
It's also possible that the reason he's struggling is because other teams are increasingly shackling him, that his colleagues are finding it increasingly difficult to get the ball through to him as a result, that defenders have learnt to anticipate what he's going to do next and how important it is to throw themselves at him in order to block his next shot.
There are a score of different potential explanations for his relatively poor scoring form, fatigue being just one of them. So let's just stop making assumptions and leave it to Poch to decide what's best for him shall we? He is after all much better qualified to judge than anyone on this forum, wouldn't you agree?