The majority of Sharp's goals for Scunthorpe and from what I've seen for Doncaster are from wingers that get to the byline and pull the ball back allowing him to stay on side and to use his strengths. If played in a way that allows him to stay in the box he shows repeatedly he's a very decent finisher and most of the time he'll get a shot away on target, often without needing much space.
We've currently got and have had two of the best wingers in the league in our squad and if we chose to play a different way I think he'd have fitted in comfortably. It's rare we do get to the byline as most of the time the instructions appear to be to get in a cross from relatively deep for Henderson (Beattie before him).
Whilst we're in the mood for comparing the two players we should try and look at the bigger picture rather than a 10 game snapshot:
Imho Henderson hasn't formed a decent partnership with anyone yet since he joined us and is still guaranteed a place in the side, many fans are of the opinion that the team suffers when he plays as our tactics and style adapt to try and suit him.
At this stage they've played nearly as many games as each other for us in leagues and cups with just 1 goal to split them, considering Hendersons taken a few penalties for us I don't understand why some peoples opinions are so polarised when discussing the two players:
Henderson - 46 games for utd in league and cup - 14 goals
Sharp - 48 games for utd in league and cup - 13 goals
Careers:
Henderson - 196 league and cup games - 73 goals ~ 0.37 goals per game
Sharp - 165 league and cup games - 82 goals ~ 0.5 goals per game
Although Henderson played in the premier league other appearances include playing for Swindon, Gillingham and Brighton and he's 5 years older than Sharp yet has only managed approx 30 more league starts which I think is important.