Left back or LWB is definitely not a concern imo. Young was immense as a left wing back on tour and I think he would be first choice in that role at the moment. He only moved over to the right when Valencia got injured, and although he provides decent cover there and James can take over as LWB, I think the team suffers a bit. I think Youngs' versatility is a double edged sword for LVG. He can play on either wing, as a 10 or even up front as he often did for Villa, but at the same time LVG obviously see's Young as his starting LWB and that leaves a £27 Million player sitting on the bench (when fit). It will be interesting to see quite where Shaw and Young will fit in together. Maybe Shaw will be given the left sided CB role? But then if Rojo comes in? His headache is going to be where to fit them all in.
It's easy to see why LVG thinks it's a well covered position.