I think what is interesting is that Pep is beginning to play the same system he installed at Barca. Two attacking wing backs, one center back that pushes the ball from the back (Pique/Stones), another one that cleans up the mess (Mascherano/Otamendi), a 6 that plays in front of the defense (Busquets/Fernandinho), two playmakers in front of him running the show (Xavi/de Bruyne and Iniesta/Silva) and 3 strikers.
I think the key is how de Bruyne and David have gotten used to their new position, a position they had never played at before.