Yep AVB's "system" was all based on statistical analysis. 11 hardworking players who press high up the pitch and win the ball back, and then create chances for efforts from outside the box instead of breaking the opponent down with passing. You rarely concede because you set up with a high press but most of the players behind the ball. It does sound like it would work on paper, when you remove the psychology of the players and fans from the equation. And there you have the problem with AVB's strategy. In statistics there are always the occasional outlying results - the games where none of the shots go in. The average game you would probably expect around 2 out of 20 or so long shot chances to find the net, but of course you have some games where 3 or 4 go in, and others where only 1 or none do. Those results, imo, sap the morale of the players, because it feels like your team can't buy a goal even when one is needed. You rely on luck, for lack of a better word (maybe statistical probability would be better), to help the ball find the back of the net.
It's like using a machine gun to shoot at a target a mile away - it is statistically probable that one of your bullets will hit the target if you fire enough times, but you aren't doing anything yourself - just getting lucky when you hit it. How different is that to carefully aiming with a long range rifle, adjusting the scope according to the current conditions, and firing a perfect shot? That's pretty much the difference between AVB's approach, and someone like Wenger's or Guardiola's.