this idea of needing a plan b in the form of a big man is a bit of a myth really, when was the last time man united had a big man striker, i can't remember us ever having one of those in recent years, if you have a succesful way of playing and good players that fit into it then whats the point having a striker sitting on the bench who is the complete polar opposite of your style of play just for the sake of a plan b, you don't see barcelona signing crouch or zigic for a plan b, in any case centre backs these days are such monsters that the style of play of peppering the box with crosses for a big man doesn't really work anymore, not against good teams anyway, if there is 10 minutes to go in a game desperate for a goal and you want to bombard the box with aerial balls can't you just put one of your centre backs up there.............