I have him around #21. On the negative, most of his fights were at lower weights, his overall record was an uninspiring 93 and 25, thus losing well over 1/5th of his fights, and few would argue he'd even compete at HW today, as opposed to lighter weights. That said, he beat (a far past prime version of) arguably the greatest HW ever in Joe Louis, gave another ATG arguably his most epic battle in Rocky Marciano, won as many times as he lost to another top 25ish ATG in Jersey Joe Walcott, and beat a whole host of several era's top contenders. While he was only champ about 2 years, few people realize he actually made 8 successful title defenses of the belt. That would be in the top 15 all time for successful consecutive title defenses.
Bob satterfield was a middleweight too. And he didn't even have 20 fights. He wouldn't become a heavy weight till years later. He wasn't a title defence for Charles either. Charles beat Bob to get a shot at the title.