Theres lots of guys that could be added.
Sugar Ray Leonard
Depends if they want to spend the money or not to produce them
I imagine Foreman and PBF would be huge hits.
Then maybe add some cut autos if guys like Arturo Gatti and some high end Tyson memorabilia cards and I think it would be a decent product!
Hell maybe even have an auto subset of guys from movies.
Deniro auto of him playing jake lamotta.
Dolph lundgren, mr T, Sly Stallone, Carl weathers from the rocky movies.
Russell Crowe from Cinderella Man
Wahlberg and bale from the fighter
Jon Favreau from Rocky Marciano
Maybe Will Smith from Ali
Again I am not saying they should do all of this but I am sure with the right guys the product would be quite popular!