Nothing against Wil or Daisy, I don't think any actor/actress could have saved the characters written.
But holy crap, young prodigy stories have so much potential when you begin writing . . . Just create a young prodigy, and then think what problems the young prodigy will run into. No one listens to them because they are young, Overconfidence and inexperience leads a really bad decision (or bad execution of a good decision) leads to horrible results. Knowledge without experience has so many great story possibilities. . . Why ruin it with creating a Mary Sue?