I suspect Haruki will be the top when the relationship between him and Yuu gets that far. As far as power bottoming I would find it to be strange for Yuuichi to be a power bottom when he is very timid and slow with intimacy in Sho's route. It be kinda silly if Yuu is that cautious with someone who has been his best friend since childhood, but then throws himself into Haruki's lap after just starting to get to know him. But who knows maybe the wolf is just that irresistable.