To be fair to LVG and put him into perspective. Is LVG a terrible coach? I don't think so, he has had enormous success both at club and country level. Could he be out-dated, possible and I won't drill into it.
Man Utd was lacking capability on ball possession and we didn't know how to pass the ball, so LVG was a good choice. We were terrible in our passing game does not mean it was entirely LVG's fault, it could be many factors. I think it was due to Mourinho's availability that prompt the club to haste his departure, although I doubt he would be able to drastically improve our game given that he has failed miserably on MF procurement, so relying on Fergi era of ageing MF won't make the cut.
Assuming we keep LVG for another 3 seasons and should the club spend another 200m on MF improvement given that he has failed in 1st attempt, I don't think so.