Would you like to know why Deron was able to open up the flow of our offense so well? Because defenders had to respect him, he could pop up for a jumper at any time OR drive past them and get to the lane. Marshall can do neither of those. College offenses are much, much different than NBA offenses. We NEED a player that can create something...Marshall can't do that. IMO, Marshall is going to struggle mightily due to his lack of a shot in the NBA because of the difference of offensive styles. Everybody is athletic in the NBA, defenders are going to lay off him and he will maybe make 30% of his shots...if we're lucky. That causes defenders to cluster in towards our big men more, the same damn problem that we have right now.
Also I'm not sure why you think that the offense would stay the same with Rivers...have you seen him play? He's a dynamic creator with a tight handle that does have the ability to pass...trust me. That just isn't his role in Duke's offense, he's being asked to be their primary offensive source. His job is to score, and he does it well. Rivers definitely can create, do you know how many times I've seen him drive and make a nice pass to Mason Plumlee (has the worst hands ever) only to see Plumlee fumble with it and then miss a layup? Anyways, Rivers being able to drive and shoot (like DWill) will open up the passes to our interior because the defenders will have to respect him. Obviously Rivers can't pass like DWill, but I can guarantee you that if he played PG in the NBA he could average ~5 apg no problem...probably more. Anyways, the point I'm getting at here is that a PG that can drive + shoot + dish will always be able to create more opportunities for his teammates than the guy who can just pass.