There was a reason the Ravens passed on him as a HC. There was a reason 30 other teams also passed. Like their father before them the colorful Ryan boys were born and raised to coordinate someone elses defense, not be the face of an entire franchise. To be successful they need to perform in the background, out of public sight, under the strong presence of an in control HC and savvy GM. They simply lack the big picture intellect and deportment to be viable HC's at this level. Rex has clearly had the most success of the two, but credit for much of that goes to the braintrust behind the Ravens (Ozzie) and the LB through whom that defense has run for over a decade regardless of who was coordinating it.
Woody keeps making the classic ownership quick fix mistake of trying to select his HC by poaching from the coaching ranks of an organizational program that was successful for many other reasons than his shiny target...and expecting to strike lightening in a bottle. Herm (who was merely a scout turned position coach with Shotsie in KC and position coach for Dungy in Tampa), Eric (who was a ball boy to position coach to one year abyssmal DC with Bill and Tom in NE) and now Rex (who was a 2nd year position coach when Billick and Lewis and Nolan but mostly and Ozzie and Ray built a ferrocious defense in Baltimore that despite all that talent hasn't won a ring in a decade including Rex 4 years as it's DC).
Try building an organization and philosophy from the top down that can grow your own coaches or try identifying a bright young mind who has made a demonstrable difference somewhere their needed to be a difference...or just hire someone who has already proved they can get the job done as a HC. Quit trying to grab stray threads off someone else's coatails...and PR spinning them into a superbowl winning formula you can feed short term to your starving fanbase and that cackle of mediots you pander to.
And FWIW Fatso will never learn from his mistakes anymore than his illustrious sire did. Them apples didn't fall far from that tree...