You could go to 50-0 the way Brian Neilson almost did and it means nothing and although Holmes was not near as bad he still avoided the best of his era, never unified vs Tate,Dokes,Weaver,Thomas,Coetzee, gave up a title not to fight Greg Page, fought many novice fighters in title bouts 2 guys with 10 wins, 5 with 14 wins and under and had 3 disputed or close wins that he never rematched and 2 were vs guys with 16 fights I think Holmes would have lost to some of the guys he avoided (matter of styles) instead he let them pick each other off and still pick and chose and we are talking about 1 era here.
....and even though it still wouldn't have beaten Louis's 25 title defenses, it's closer to say he was only 3 title defenses away than 5.