In the entire history of the draft, 1965-current, there have been exactly three #1 overall picks to make the Hall of Fame: Baines, Junior and Chipper. That's in over half-a-century. Harper will be there someday.
Zero pitchers drafted first overall are in Cooperstown. Cole leads all #1 pitchers with 41.2 WAR, followed by Price 40.3, Strasburg 32.3, Benes 31.5, Moore 27.9, Belcher 26, McDonald 20.8.
Grim pickings...