AZ had already been doing rather well under Co Adriaanse, who took them from 10th to 5th to 3rd. If LvG's achievement was winning the league with AZ, then it should be noted that he did so only after changing tactics.
Co Adriaanse and Louis van Gaal were two of a kind, they're 'soul mates', brain mates actually, they think alike, they worked closely together. Co Adriaanse also could make not so very good players look like very good players who play very well. Adriaanse took Willem II to the CL and even scored a few points in the CL, you can google how small a club Willem II is yourself. It's not such a big name because it's a very difficult character to work with, but if a club lets him work under his own conditions, he can do special things, and he did it again at AZ. Compared to him Van Gaal is easy going, laid back, extremely flexible and nice and polite to the press. That might explain why he isn't an internationally known manager, it's not because what he can do with a group of players. AZ was such a club, and he really overachieved. His footballl with AZ was as gorgeous as it comes without players with the special skills of Messi etc.
From the horses mouth in a 2009 interview:
The interview can be read here (behind pay wall)
or here
Like at AZ Alkmaar, LVG's most recent successes, be it with the national team, or here in the second half of last season, happened when he was forced to change his preferred style and adopt a more pragmatic approach. Make what you will of that.
Adriaanse put on a great show of attacking football, Van Gaal made them title contenders. He did that before he changed tactics, he changed tactics because it suited those players he had a couple of years later better, he had signed young Pelle, but he was going trough a difficult spell in which nothing worked for him, his back up signing Ari suddenly did very well, and he made a line up that suited his players best. He has always done that, but most tactical changes were within the bounderies of 4-3-3, 3-4-3, pointing forward, pointing backward, centre forward behind the wide forwards, centre forward up top. But he never had to sacrifice 4-3-3 in any form to suit the players because Ajax and Barcelona can make sure he has the players who are suited by some form of 4-3-3.
The aim of the game is to win, preferably in style. At the end of the day a win is worth 3 points. Different people will enjoy different aspects of the game. There is no moral high ground, only different approaches and preferences.
I'm not taking a moral high ground. I'm pointing out that possession football gives you the initiative, and that's a very practical advantage. For example last spring, when Liverpool had to score a goal in the last 10 minutes, and United was just having possesion and had them chasing the ball without any succes. Or when you for some reason find your self behind 2 goals after 4 minutes. Any counter attacking team would feel a bit of panic, but if you're playing the possession game well, it only means you have 86 minutes left to score 3 goals and you can just start doing what you do best.
Each style has it's strong and weak points. Possession football over-complicates things needlessly and requires a very high quality of players, especially in the final third. Teams like Barcelona and Bayern make it look easy because they have Neymar, Suarez and Messi or Robben, Lewandowski and Muller to break down defenses. Guess what? With players like that a team could play any style of football and would still come out on top.
No, they don't. Barcelona was a mess before Enrique took over, Guardiola didn't always come out on top with Barcelona either, and with Bayern we've also seen that Enrique did a better job than him with very good players.
Especially players like that can profit from a complicated organization where there's not relied on their individual brilliance. There's an advantage to be gained from having those players really playing together well. This could be either possession football or counter football, the difference is that possession football only exists with a complicated organization and players playing together well, and counter football could do without it. In that case it's not as good as it could have been, but can still be good.
Counter football is just more suitable for mid and lower table clubs, because if you have to win every match, you can't afford waiting for the other team to attack to make goals.