My prior posting was in error.
you reference the Bills Super Bowl era defense to support your arguments, however the inverse is true.
In spite of the all-star caliber talent on that defense, it consistently ranked in the bottom 25% of the league. Part of the reason is that defense was manhandled by strong running teams due to the undersized DL, especially the nose tackle.
To compound the problem, interior OL have increased in size by 25 -50 pounds from that era.
Your argument that size does not matter is just a bit shortsighted. To maintain that Fletcher will be as productive in a 3-4 where the scheme requires him to take on 340 OGs is just asinine. He has been productive for the Bills because he has been protected by Adams and Williams.