I think Zadina is by consensus # 3 because he has some elite stuff going for him that other players do not have. For example an elite shot + ability to protect the puck and create his own scoring chances. In addition he is a very good skater, can lead the rush and has decent size. The only knock against him is his play without the puck and his defensive game. In other words he still needs to round out his game to fit the pro style of hockey and play effectively against men. But the raw skills he has cannot be taught.
On the other hand players like Kotkaniemi and Wahlstrom have good attributes like stickhandling abilities for the Finn and a great shot for Wahlstrom, but both are said to need work on their skating....thats a bit of a red flag.