I think it's quite difficult to compare. At Chelsea the midfield provides an awful lot of goals, in fact so do the defence. Whereas the clubs Lukaku has been at rely more on the strikers scoring the goals.
I can see why Lukaku was loaned out though. There is no denying he will be absolute quality and probably the best striker in the world in a few years but he is still quite raw and he does do things in a game that more experienced players wouldn't.
Maybe he would've scored more than Torres has he played the same amount of games us but i just think for him to be getting first team football in this league at two top half teams is a good move for us. It saves him fighting for a place with Ba, Eto'o & Torres whereas loaning him out means he is pretty much guaranteed a start every week.