I realised this when Man Utd sold Beckham. Solsjaer, Scholes and Giggs playing in a system with 3 forwards rotating and playing off RvN. One moment, Solsjaer was a winger, the next, he was creeping in and poaching off loose balls. I realised then that this would be hard for RvN to fit in as he didn't have the fluidity that this system demanded. So when RvN left, I was sad, but I new it was to both sides benefit. Saha had the mobility and was more fluid in blending in with the other forwards.