This is a great discussion and it's something interesting, I've never been involved in anything as deep as this.
I think we can have both Wilson and a great defense to keep winning for years and get to a few Superbowls. Wilson will have to have new rookie WR/TE/RB every 4 years or so and 1 or 2 playmakers at anyone of those positions. The O-line will also need to be replaced every 4 years to make way for rookie O-lineman to replace the ones that might demand a large contract after their rookie contract is up. In doing this we actually have more money to be put into the defense regardless of the large contract that Wilson will sign plus the salary cap will go up at almost an average of 30 million per season which will pay for Wilson's 20-25 million a year contract by itself.
We can keep Earl, Sherm, Kam, and Wagner, and keep some good playmakers on defense, but draft to keep churning out replacements for everyone else every 4 years.
Chart shows this below:
This shows Superbowl winners during the start of the salary cap era in 1994
*starts on the year they played a full season
Year – Team: Quarterback (Years Played), Running Back, Wide Receiver, Defense DVOA
1994 – 49ers: Steve Young (1991-1998), Derek Loville, Jerry Rice, #1 Defense DVOA
1995 – Cowboys: Troy Aikman (1989-2000), Emitt Smith, Micheal Irvin, #5 Defense DVOA
1996 – Packers: Brett Favre (1992-2007), Dorsey Levens, Antonio Freeman, #3 Defense DVOA
1997 – Broncos: John Elway (1983-1998), Terrell Davis, Shannon Sharpe, #8 Defense DVOA
1998 – Broncos: John Elway (1983-1998), Terrell Davis, Rod Smith, #20 Defense DVOA
1999 – Rams: Kurt Warner (1999-2001), Marshall Faulk, Isaac Bruce, #3 Defense DVOA
2000 – Ravens: Trent Dilfer (1994-2007), Jamal Lewis, Shannon Sharpe, #2 Defense DVOA
2001 – Patriots: Tom Brady (2001*-current), Antowain Smith, Troy Brown, #13 Defense DVOA
2002 – Buccaneers: Brad Johnson (1996-2008), Michael Pittman, Keyshawn Johnson, #1 Defense DVOA
2003 – Patriots: Tom Brady (2001*-current), Antowain Smith, Deion Branch, #2 Defense DVOA
2004 – Patriots: Tom Brady (2001*-current), Corey Dillon, David Givens, #7 Defense DVOA
2005 – Steelers: Ben Roethlisberger (2004-current), Willie Parker, Hines Ward, #3 Defense DVOA
2006 – Colts: Peyton Manning (1998-current), Joseph Adai, Marvin Harrison, #25 Defense DVOA
2007 – Giants: Eli Manning (2005-current), Brandon Jacobs, Plaxico Burress, #13 Defense DVOA
2008 – Steelers: Ben Roethlisberger (2004-current), Willie Parker, Hines Ward, #1 Defense DVOA
2009 – Saints: Drew Brees (2002*-current), Pierre Thomas, Marques Colston, #17 Defense DVOA
2010 – Packers: Aaron Rodgers (2008*-current), Brandon Jackson, Greg Jennings, #2 Defense DVOA
2011 – Giants: Eli Manning (2005-current), Ahmad Bradshaw, Victor Cruz, #19 Defense DVOA
2012 – Ravens: Joe Flacco (2008-current), Ray Rice, Anquan Boldin, #19 Defense DVOA
2013 – Seahawks: Russell Wilson (2012-current), Marshawn Lynch, Golden Tate, #1 Defense DVOA
2014 – Patriots: Tom Brady (2001*-current), Jonas Grey, Rob Gronkowski, #12 Defense DVOA
Top 5 Rank Defenses DVOA won 11 out of 21 times. 9 of the Superbowl games that had a top 5 defenses also have 8 QB's that are in or will be in the Hall of Fame (Steve Young, Troy Aikman, Bret Favre, John Elway, Kurt Warner, Tom Brady, Ben Roethlisberger, Aaron Rodgers.) The 9th that is not considered yet for the Hall of Fame is Wilson at the moment.
Top 6-10 Rank Defense DVOA won 2 out of 21 times, with Tom Brady and John Elway at the helm.
Bottom 11-25 Rank Defense DVOA won 8 out of 21 times with Tom Brady, John Elway, Peyton Manning, Eli Manning, Drew Brees and Joe Flacco