It's not so much that Wotte played the diamond or Poortvliet played 4-5-1 (or 4-3-3, apparently) but it was the fact that they played these systems every minute of every match. A decent manager/coach has to be flexible, from game to game and even in periods of the same game. It's called a plan B, plan C or plan Z!! A rigid 4-4-2, would be just as bad IMO. I do prefer 4-4-2 as a basic formation but if it's not working, then it needs to be changed. So in answer to the question, I would not retain Wotte.