Marshall isn't just an empty assist guy -- he, like Rubio, has the ability to make everyone around him better. UNC fell apart bigtime after Marshall hurt his wrist. Minnesota is an absurd 5-17 (or so) without Rubio. They fell apart the same way UNC did.
Yes, he can pass well in the pick and roll, but in the NBA, teams are going to make him shoot the ball by going under the pick. He will struggle
This^ If the Blazers take Marshall they're going to have to surround him with a lot of catch and shoot guys and put them in motion. The Pick and roll is predicated on the guard being a threat to stop and shoot it himself forcing a defender to choose between closing out on the ball-handler or staying with the pick setter who (theoretically rolls to the hoop or pops). If Marshall can't shoot it then there's a very real possibility he just turns into another Sergio story ... but if on the other hand he can develop some kind of jumper to keep defenses honest he could be a really good player. For me it all comes down to value. At 11 I think he's a pretty good bet, at 7 I think there are better players still on the board and I don't want to see the Blazers get too caught up in drafting for need.
And that's why I was comparing him to Cota. You can be an assist specialist in college and get by with a dodgy jumper. You can't do it in the NBA. Sergio was a great drive-and-dish guy in his rookie season, but soon teams figured out he couldn't shoot a lick and they back off him, taking away his ability to drive. People keep comparing him to Andre Miller, but Miller has a pretty solid jumper from about 15 feet and within. He also has a great postup game. Jason Kidd is another guy who didn't have a great outside shot coming out of college, but both he and Miller averaged 7 or 8 points more per game than Marshall.
Marshall isn't known for having an offensive game because he doesn't look for his own shot much. He's a traditional pass first PG. Ed Cota was 6'0" with shoes standing on a phone book. Marshall's 6'4".
At UNC he ran the offense and looked to pass every opportunity he got -- in his two season he's averaged about 5 FGA per game. He can develop his jumper much like Andre Miller did.
Jason Kidd and Rajon Rondo seemed to manage it. And Ricky Rubio was doing okay. Every player has a weakness, it depends on how they compensate for it. I'd rather have a PG who can't shoot than one who does nothing but. Sergio was (a) maddeningly inconsistent, (b) totally invisible on defense, and (c) not really put in a position to succeed. I wish he could've had the chance Rubio's getting. Miller was a player of the year candidate at Utah, lest we forget, and was taken higher (#8 even though he was in the same draft as Baron Davis and Steve Francis, and would've been higher otherwise.) Kidd was seen as a once-in-a-generation talent. (And basically was.) He wasn't just big and a gifted passer, he was incredibly fast and a lockdown defender. However, neither of them had the talent around them that Marshall had, and the job of keeping them all happy. The most common comparison for Marshall that you haven't mentioned is Mark Jackson. I've never thought of Miller as particularly slow, but Jackson was, and also couldn't shoot. He was also drafted mid-first-round, like Marshall is projected. He did okay, as I recall.
I'm perfectly fine taking Marshall at 11 (our likely landing spot with our pick) it's when it gets into the top 7 (New Jersey's likely landing spot) that I think the bang for the buck or at least the risk and reward starts to tilt away from Marshall's favor.
Kidd averaged close to 16 ppg in college. Marshall didn't even average 10 ppg. Kidd was a pure point guard, but he could also score when needed. His biggest flaw was his inability to shoot the three, which he later addressed. Rondo might just be exposed next season. It will be the first time we will see him without three future HOFers around him. I think just about anyone could have played the point for Boston and looked good. Players that can't shoot don't make it the NBA. Omar Cook? Sergio? Ed Cota? Sergio didn't succeed because he was terrible. The guy had an inconsistent outside shot, yes, but he also couldn't finish that the rim. His offensive skills were severely lacking. He had a great feel for the game, but that was about it. Nate had him as the primary backup for almost a full season and he couldn't do anything with it. Jackson had the advantage, like Rondo, of playing with some amazing teams. He as on the Knicks with Ewing, and the Pacers with Reggie Miller. The thing is, he was discarded by both teams. Pure point guards are great, if they can also shoot the ball. John Stockton Jason Kidd Steve Nash There's a reason why most of the "pure" point guards are also HOFers.... because you have to be THAT good to make it in the NBA as a passer, otherwise you're just another Ed Cota.