Len converted around 40% of his field goals playing with his back to the basket in the post. While this isn't a high percentage, you have to realize that Maryland was playing an offensively challenged big in Alex Padgett next to him who couldn't space the floor and just took up space in the paint. Maryland's offensive in the half court basically consisted of swinging the ball around the perimeter a few times and then jacking up a bad shot or dumping it into Len. When he got the ball, defenses were able to key in on him and due to the lack of spacing, weak side help was often there in a hurry which hurt his efficiency.
Len is much further along in his offensive game than Nerlens, the kid averaged 17.5 points per 40 during a down year. If you think Len is awkward around the basket and can't score, then you need to watch more tape on Noel.
He dominated Noel because the kid is too weak to compete on the block with his stick frame and couldn't use his athletic ability to overwhelm an opponent that actually has NBA talent. Plumlee isn't a scrub either, he's an athletic big that will probably be a rotational guy in the league for a long time.