I can see St. Louis going after Kalil because Sam Bradford cannot keep getting hurt and be expected to remain in the league a couple more years. If Fischer went there even partially based on the idea they have a franchise QB then he's going to have to help protect him. It's easier to get impact players in free agency, especially when you have a big name coach like Fischer.
That being said, no way Blackmon gets past the Vikings at #3. Ponder needs weapons, if youre going to play in a division with the Packers and Lions you need to be able to move the ball and put up points.