Most analysts are very confident that Fields will drop to 4.
Most analysts are not making the 49ers pick. I'm fairly confident that the Jags will take Lawrence (because if they don't, they are idiots). After that, everything is guesses, some guesses are better than others. SF could surprise everyone and take Pitts, but it's unlikely. More likely they take a QB, but NOBODY aside from John Lynch, Kyle Shannahan (sp?), and the rest of the 49ers staff has any certainty about that. Same thing for Atlanta, Cincinnati, Miami, and so forth.
Also remember that the big 'surprises' on draft day are usually when a team makes a pick that the analysts did not expect. Some will love it, some will hate it, and no one, even the GM of the team making the pick, knows how it will work out. Did anyone predict just how good Aaron Rodgers, Russell Wilson, or Tom Brady would be, or how bad Tim Couch, JaMarcus Russell, or Akili Smith would be?
It's like Socrates saying that he knows very little, but knowing that, feels that he knows more than most people who don't get that.