From what the vizards said in this chapter, it seems that all they are trying to do is stall for an hour. Their plan might not actually involve ichigo beating his hollow side. Also, i wonder what the battle in the outside world has to do with the one going on inside ichgo. Does fighting the outer hollow weaken the inner one somehow or are they simply trying to prevent the outer hollow from causing chaos? I think one possible explanation is that they are trying to distract the hollow so that he cant solely focus on the fight against ichigo with in his mind.