I would rather play a class player out of position if that would benefit the team as a whole. PDC isnt class IMO and I would play Vidal as RWB, yes, given the alternative that we also have a very solid solution for CM in Asamoah. Fielding 11 class players > fielding 11 players on natural position.
It's a bit like...
Chiellini as LB if we sign a new world class CB..
Off topic; It's about time we lower the age of this team.. Building for the future means -25 year old players. (Asamoah, Isla, Pogba, Verratti) but also regarding the other positions such as LB, CB, CF, SS IMO.. Anyone above 25 should be immidiate world class ei Barzagli otherwise I would go for lower standard players being years younger. Like Arsenal - it's not like we're gonna win CL next year anyway! (So no - Kolarov is too old IMO)