I'm devastated that Memphis hasn't burst onto the PL scene because he definitely has the potential and has shown it at times throughout the season and moreso for the Dutch national team and PSV.
However, this shouldn't be ok much of a shock that a young, creative player has struggled in this United team.
Di Maria looked like Tom Cleverley, Nani played like Bebe, Rooney has for the most part looked like a Sunday league player, Januzaj forgot how to dribble with the ball whilst Young, Valencia, Fellaini... Players who are way less talented but able to play less with instinct and follow rigid instructions, have prospered.
I remember watching the Bayern team under van Gaal and being extremely impressed at how controlled they were in their approach to the game so I know our system CAN work with creative, instinctive players but it seems the United players, Memphis included, have been unable to adjust so well.
The fact Robben and Ribery have also featured in Pep's teams would suggest they are flexible enough to play both styles.