Does support strikers always have to be judged from their goalscoring ability? If a player can master exatly everything in that position excellent but he can not by any chance even hit the post, wouldn't you want that guy? Who cares what part he plays when a goal is scored, as long as he is part in it, what does it matter if he touches the ball last?
Zlatan played well his first year, I'd say that even if he had only scored 6-7 goals. Just as he is playing well with Inter now.