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Leave Women's Football Alone!!!
United don't need either a striker or a winger for me (Not as top priority anyway) and when they have wingers they are 'proper' out and out wingers usually. Bale can fit that. None of this faffing around and letting him play behind the striker crap. Just let him play as a winger. In Youngs first season with United he had a pretty good one and he still cut inside and had shots on target whilst putting in crosses. Bale would be able to do this but to a more devastating effect. He'd slot much easier into the side than Neymar would who would be a bit like Kagawa in the sense that it would take him a bit longer to gel.
Chelsea need a striker still which is fairly obvious and Neymar could slot in there as part of a dynamic front 3, but you'd have to push out one of Mata/Oscar/Hazard. Maybe as Mata ages he can do what Cazorla has been doing and play a little deeper though.
City could have Neymar - ST - Aguero as part of a 4-3-3 combination which would also be deadly.
I think we need both a winger and a striker (to go with a CM). It would take Neymar as much time to gel as it did Ronaldo.