He's not the finisher Lukaku was for us.... tbf lukaku is a very good finisher - That's not in dispute.
The problem with lukaku to apply his "finishing" prowess means that he needs to have the chance created to do it. Against poorer sides his unintelligent movement isn't negated as much as it is when he plays against proper defenders. He gets caught offside way too often, defenders show him on his right foot..... he just doesn't get free to take his shot because he also can't create for himself.
DCL can score against better sides because he apply himself as a traditional centre forward, competes for every ball, wins headers, feeds the other players and gets available for the second balls.
Totally different type of players but I know exactly who I would want up front against the likes of Liverpool, Chelsea, etc.