I said this summmer that i preffer him to Ramos, nad about 80% of people who
Rio was playing regular football as a CB at 23. His RB stint damaged his confidence and peoples perception of his ability, which he's still fighting against now. He was ready at 21 and should've been trusted, and we would've seen this a lot quicker.
At the age of 23 Rio was starting in World Cup 2002. Smalling missed out in place of the likes of Phil Jagielka and Gary Cahill.
He was ready, but we had Rio and Vidić, that was the problem. We couldn't just removed them, they were still playing well and didn't deserve it. Plus the injury problems didn't really help and Smalling would often play as RB just after injury, so he can settle. Smalling should have started regularly in Moyes's season, as neither Rio, or Vidić didn't play really well and he was our best CB already.
I think it's half and half, LVG isn't responsible for Smallings ability or development so much but he is responsible of using his strengths to get the best out of him. Smallings key strengths is to bully 1v1 situation outside the box from standing, jumping or running with/after the ball and the way LVG has changed United's play from possession and team positioning means that 90% of Smallings defending is 1v1 outside of our box.
Smalling is also good at defending in the box, as he has proved it a lot of times before.
Of course LVG is partly responsible for some staff, but I have a feeling that lot of people thought that Smalling was just an average defender and LVG made him really good, which just isn't true.