When a defender heads the ball he generally just stand under the ball and sends the ball up the pitch. When a forward scores a goal from a header they will usally turn their head very quickly and 'wip lash' (For want of a better word) the ball adding further force and changing the direction that the ball is travelling which is achieved by a combination of upper body strength and the players neck muscles, which obviously must be very strong.
When dublin first went to villa he scored a lot of goals with his head, he then broke his neck and as any villa fan will tell you, he went from a God to a donkey, and rarely scored again. Now concidering the way a striker heads the ball, I can understand why he aint so confident about using his neck to thunder a ball in to the back of the net and it is not unreasnable to expect his neck to be weakened after being broke, so dont ever expect him to score goals in the way Deano & les did cos it will never happen.
Did ma concider this when he bought him in. I doubt it, and does the 2H's realise this, No chance.