This is a good point.
I'm sure the lad is versatile, but from what I have seen, there is absolutely no doubt that his best football has come from when he has been playing in the position that Pienaar will mostly occupy this season.
To me the logical position would be RM. From what I've seen he plays there more than LM, but then I've only really seen him for Belgium.
BUT Pienaar is a great LM for us and Naismith or Osman can play comfortably behind the striker (although I suspect we'll see Fellaini there). As we have no pacey overlapping fullback on the right hand side, a touchline-hugging, skilful, pacey winger would be the perfect solution. This guy is right footed, fast and skilful, so to me he'd be a perfect RM.
However he, like Pienaar, Osman and Naismith can all play across the front line and that's a tantalising proposition. It would make us a lot less predictable, and that's a very good thing as if we've been anything these past few seasons, it's predictable.