Well Pac Man is short.. which may hurt his stock.. but I still dont see him getting out of the first. a late first day pick i would think.. at the worst.
Castillo could move up if he makes a good showing at the combine.. and there isnt much depth at all at DT.. so if there are teams out there that really need a DT... his stock could rise.
Clayton could beat out Williams if Williams has bad 40 speeds.. which is very possible.
And Derrick Johnson COULD fall to the mid first.. but I doubt it. It would take some bad workouts. Or a bad attitude that no one knows about yet.
All in all.. I think this mock is just an attention getter.. "come look at our site!" kinda thing.. it will be more accurate when there is real information to base it on.