[BostonCard]

I disagree with the entire premise of your post.

The great coaches don't "know the questions and the answers".  The difference between the great coaches and the middling coaches is that the great coaches know their limitations and can identify the people who can fix them.  Chip Kelly was an offensive genius, but he was smart enough to find a good DC and let them run the defense.  Same with Jim Harbaugh; the story of Richard Sherman is that one of the reasons he transferred to defense is that it put him outside of Harbaugh's purview.  Even Nick Saban knew that he didn't have the answers for the changed to college football (spread option, tempo), so he hired an offensive coordinator who modernized his offense.

The great coaches don't know everything, but they know what they don't know and hire accordingly.

BC 

[BostonCard]

I disagree with the entire premise of your post.

The great coaches don't "know the questions and the answers".  The difference between the great coaches and the middling coaches is that the great coaches know their limitations and can identify the people who can fix them.  Chip Kelly was an offensive genius, but he was smart enough to find a good DC and let them run the defense.  Same with Jim Harbaugh; the story of Richard Sherman is that one of the reasons he transferred to defense is that it put him outside of Harbaugh's purview.  Even Nick Saban knew that he didn't have the answers for the changed to college football (spread option, tempo), so he hired an offensive coordinator who modernized his offense.

The great coaches don't know everything, but they know what they don't know and hire accordingly.

BC