I've heard it too (I've also heard plenty call him Woody), but just because something is well known/discussed doesn't mean to say it's actually true, that's how myths develop. I also wouldn't necessarily link the village nickname to a lack of intellect.
Doesn't apply to all, but Footballers are generally seen as very immature, or at least the environment is and they do a lot of very stupid and silly things for effect to fit into their environment, including playing up to stereotypes. The Teesside accent also has the ability to make even the most intelligent person sound like a complete dumb-ass, so I wouldn't necessarily equate the nickname or stories of dressing room banter to his actual intelligence levels.
I don't know him, so personally I wouldn't jump to that conclusion (although the evidence of his team selection v Swansea is damning evidence!
).