Sorry I didn't answer before, yesterday was a bit crazy and I didn't have a chance to, and I'm sure there's been loads of posts in between but you make a lot of interesting points so I wanted to answer.
First of all, I just want to clarify that I watch very few of VG's press conferences or media statements or whatever, and I hardly read any of the press about the PL, so most of what I'm saying is my opinion on the matter. Of course I know he talks about philosophy and process (impossible not to when you're on the Caf), but that's pretty much it.
I don't agree with your take on Van Gaal who took over with no longterm vision, and I especially disagree with the point you're making about the systems. For me, Van Gaal has a very clear idea which is to play possession football at its most 'pure' interpretation, by confiscating the ball from the over team and by minimizing the exposure to risks of the team in this manner. I don't believe he's yet found the perfect balance between this defensive game (which I think, until we lost all our players to an epidemic of injuries, we did very well) and a more speedy transition to attack, and he's very cautious in his approach, but I do think his 'philosophy' is quite clear (and I think it's a bit disingenuous to say otherwise to be quite frank). Whether or not this approach is the right one for the PL is another matter, but I'll talk about that after.
So coming back to the systems, the reason I disagree with you is that I don't believe his vision is based around a specific system (a lot of playing styles aren't necessarily and tactics can transcend systems), I think he believes that his approach can function in different systems depending on who's available and who the adversary is. Basically, depending on the context, he'll set up the team in the best manner to deliver his 'philosophy'. And I think this is rather backed up by the fact that even though the systems may have changed, I don't remember us ever actually switching our approach dramatically to another playing style and whatever the system played, the ideology remained the same. You mention the kick and rush play, but this has only ever been used as a last resource when the initial approach wasn't working, and has never (unless I'm mistaken) been our default approach in a game.
The transfers is an interesting point, though I'm less at ease discussing it as I'm not quite sure how exactly they occur. Simply speaking, I think there are certain transfers in a club like ours that aren't necessarily motivated by sporting reasons but that would be imposed due to marketing/brand reasons. I think Di Maria for example was a statement of intent by the club, and I don't believe he was ever a Van Gaal player. Falcao was a bizarre one, in that the player he used to be probably could've been great for the team, but he was finished by the time he arrived at OT. I think transfers like Herrera, Shaw, Blind, Schweinsteiger, Schneiderlin, Darmian, Martial and Memphis (though I'm a bit less sure about this one) are quite coherent, and I think the players he's promoted for the Academy also fit into this mould. So yeah, I do feel like there's a coherent approach overall, though of course it's not an exact science and transfer dealings are always a bit hit and miss.
Also, when I talk about legacy, I don't necessarily mean the next manager will come in and use the exact same set up and approach and of course he'll want to be his own man, but I think the discipline and the comfort with which the team keeps the ball will be hugely beneficial for the successor.
Now one aspect I find more interesting than whether or not LvG has a real philosophy (which to me is quite clear) is whether this philosophy is actually suited to the PL. More exactly, until we've found the ease to move the ball around quicker up front and more success in breaking teams down, I think it's going to be hard. I think in other leagues, like the Spanish or the German ones, from what I see, there's very few teams that will have the discipline or the will to spend 90 minutes defending around their box and trying to nick a goal from a set piece (I'm not even talking about teams set up to counter, loads of teams we've played this year barely even rely on that), whereas the PL has quite a few teams that know how to do this quite well. Which doesn't make the PL a better league than another, by the way, it's just that I'm starting to really have my doubts about whether the approach we have is actually adapted to the competition we're playing in.
