I dont think Wengers approach is that holistic.
Ive always agreed with the idea with them that it is mental. When the pressure is off, they perform. When its crunch time, they lose their heads.
Maybe the truth is somewhere in the middle, and I definitely agree they have had their fair share of mental balls-ups (the Carling Cup Final against Birmingham for example) but this is such a consistent trend over a stretch of a few months, that happens every season, that I think there is more to it. I can never prove it for sure without Wenger giving me a breakdown of his methods, but it happens almost like clockwork. Pressure can be defined us the title being written off or top 4 being written off, but in either of those cases they have a strong final 2 months. It doesn't matter whether we are 13 points ahead of them, whether they are way down in 6th, or whether they are pretty certain of 4th but may get 3rd if they really push for it. It always happens.
Unfortunately for them last year we were also strong finishers, but I do think perhaps the idea of them being poor mentally (which I agree with) gets tied up with their strong finishes a bit too easily. Because broadly speaking, you can see teams that like to start fast and teams that like to build to it. A Fergie team used to always build to it, but Mourinho came in and was a fast starter, so Fergie had to alter his plans to make sure they didn't fall too far behind. Klopp always starts fast in a season. As does Pep. We have always done ok but then our performances take a notable positive turn during and after Christmas, as does Arsenal. I also think lower down for example Martinez at Wigan was always a strong finisher (and he was known for his focus around conditioning). There are certain teams that seem to always do well at certain points of the season compared to others, and I think conditioning plays a big part in that. Of course there are other managers that maybe don't focus on it as much - or maybe just want to hit 40 points as quickly as possible (Pulis) - and maybe Harry was one of those in terms of just going hell for leather without too much consideration of making the form runs predictable. But I think the top 6 coaches now, all of them are pretty tuned in to peaking and predictability around performance as much as possible, and a lot of their in game strategies derive from it too - for instance I think we play a much faster tempo now compared to earlier in the season, Swansea and WBA at home etc. Maybe we'll have the occasional high tempo game thrown in there but it may be more sporadic, where as later in the season we have tended to batter everyone and look relentless. I think our conditioning is curated as such so that the players are capable of relentless football and we can ask it of them at times when we know they can do it.
(as an aside, I'm somewhat guessing, but pretty sure Southampton will have a strong end to the season. Pellegrino strikes me as someone that has managed his squad well through rotation and puts a lot of focus on conditioning. (Likely learnt this from Benitez) So I won't be surprised to see them finish at least 12th and am not surprised that the Southampton board maintained faith with him)
Like other fans will joke at us for winning the 'Put the pressure on' trophy, as if we didn't have the mentality to get out in front early on in the season but could only play when we didn't really have a chance. Which is also assuming that Liverpool had a great mentality to get out in front but not to sustain it? I think it's more how we try and prepare our form, and the real answer is we didn't have the depth / quality to win the games we needed to when not in 'peak' season. If we did, we'd be title winners. I will say though, if we end up getting Malcolm in the summer, and Sess, I think we'll have a serious amount of depth and quality all over the park and could well push for the title. Malcolm is a key for me, because I don't think previously we would have had someone of such quality in a 'rotation' position, effectively competing with Son and Moura. If we get him, I think it shows we'll be making a serious push.