I just find the Billy Joe Saunders scenario very similar to Kell Brooks. Kell Brook put on a great performance beating Shawn Porter in 2014, then he spent 2 years fighting fringe world class contenders and the three times he stepped up to the top level thereafter, he was pretty much outclassed and stopped every time. Shawn Porter on the other hand after he lost to Brook, boxed Broner, Berto and Thurman and in 2018 whilst Brook was busy beating Zerafa, Porter regained his world title beating Danny Garcia. In his last foray into world class Brook was stopped in 4 rounds by Crawford, meanwhile Porter arguably gave Spence the hardest fight of career in 2019. To a degree styles can make fights, but Brook was at the same level as Porter in 2014, Brook declined due to level of competition whereas Porter maintained and improved his level of performance for the same reason. It's why Ricky Burns beat Kevin Mitchell and why people like Frank Lampard end up having a better careers than Paul Gascoigne. When English football teams were banned from European football after the Heysel disaster it took almost a decade after the ban was lifted for an English team to win the Champions League. Whilst a good promoter and the option of multi-titles is useful at the start of a boxers career as they gain experience, it actually harms their legacy when they reach top level due to different promoters, governing bodies and tv stations not working together. If Shawn Porter had been with Eddie Hearn from 2014 onwards, and Kell Brook with Al Haymon I believe Porter would of had the same career as Brook and vice-versa. Financially though they have probably made the same money.