I'm basing this on a number of things. Firstly, his history as a manager shows that in his career he has brought through many top youngsters and has laid the foundations for the two best teams in the world (Barca, Bayern). I also think that despite what people say, possession football when played well is the best football tactic in the world again as is highlighted by the domination of Bayern and Barca. Now obviously we are still alittle bit short if that quality but I think we have players in, Memphis, martial ,shaw etc that can all reach that top,top level and get us up to those teams.
Secondly, I think people underestimate just home much work LVG has done to make us a defensive unit, I personally think we have one of the most solid units in the league right now (Arsenal game aside) and u do think over the course of the whole season that will once agin prove to be the case. Now it's because of the improvement in the defensive game that makes me think that the attacking side of the game will come sooner rather than later. For me personally we have seen glimpses of this teams attacking potential and I think with further work and maybe a start player addition(Bale, Griezman etc) I think we could suddenly see our attack explode into life. Despite what people say at the moment, LVG does build solid, but exciting attacking teams and that's where Utd are heading.
In my opinion, we are in a waiting stage; at this time we need to wait for the talent that we possess to come to fruition as it will over the next few years, (perhaps even after LVG has gone). We are currently standing at a landmark, that I think will be looked at as huge in utds history. Similar to 2003-4 when young Ronaldo and Rooney were developing and it was just the case of waiting for the tree to bear fruit I think we stand at a similar point. Perhaps I'm being far too optimistic, perhaps these players won't develop, but I see potential in this team and its style to get right to the top of football again with the right patience and clever moves.