Not to be confrontational or disrespectful, sir.
However; a fan who says something like "The so called lineal" is disqualified from being a knowledgeable boxing fan, let alone an "expert". In dealing with facts; counting "sanctioning body" belts as true accolades tips your hand. This is a condition unique to heavyweights because the true lineal championship is empirical at the Alpha weight class. There is no belt there that holds any real meaning.
In recent times, Ali, L. Spinks, Holmes, M. Spinks, Tyson, Douglas, Holyfield, Bowe, Moorer, Foreman, Briggs, Lewis, Rahman, W. Klitschko, Fury and Usyk each has taken a turn holding the one, real Heavyweight Championship of the World. The most historically significant crown in all of sports.
During the same recent timeframe, Ken Norton, John Tate, Mike Weaver, Michael Dokes, Gerrie Coetzee, Tim Witherspoon, Monte Masters, Pinklon Thomas, Greg Page, Tony Tubbs, Trevor Berbick, Bonecrusher Smith, Tony Tucker, Francisco Damiani, Ray Mercer, Mike Bernardo, Bert Cooper, Adilson Rodrigues, Jimmy Thunder, Tommy Morrison, Michael Bentt, Herbie Hide, Oliver McCall, Bruce Seldon, Frank Bruno, Henry Akinwande, Aussie Joe Bugner, Vitali Klitschko, Chris Byrd, Frans Botha, John Ruiz, Roy Jones, Corrie Sanders, Lamon Brewster, Nicolai Valuev, Siarhei Liakhovich, Oleg Maskaev, Ruslan Chagaev, Sultan Ibragimov, Samuel Peter, David Haye, Alexander Povetkin, Bermine Stiverne, Deontay Wilder, Charles Martin, Lucas Brown, Anthony Joshua, Joseph Parker, Mahmoud (Manuel) Charr, Andy Ruiz Jr., Trevor Bryan, Shawn Laughery, Daniel Dubois and Kubrat Pulev were NEVER the Heavyweight Champion of the World. They simply never won that singular title.
They were merely contenders, (and some, not even quite that), and sanctioning body Belt Holders; which is something VERY different; and this is something people knowledgeable about boxing fully understand, without any confusion.
See this as an opportunity to learn something. Smart people don't ever waste those.
The opportunity for you to learn is that Fury had retired but still somehow managed to be labelled lineal. Not to mention it was potentially a shadow ban from UKAD. Anywya, label him lineal if you like, bottom line is AJ fought and beat better opponents.
Thanks for coming to class kiddo.