I guess fifth place all time probably defaults to Joe Bessala, the Olympic silver medalist from 1968 who fought professionally in the 1970s with a final record of 14-2-1, capturing the pan African welterweight title.
I did some perfunctory research to see if there were any standout boxers that were born in what is present day Cameroon back in the colonial era when it was under French/British/German control and their nationality would have been reflected as those in the annals of boxing lore. Couldn't turn anything up, but there must have been at least a few. Pretty sizable chunk of land in Central Africa where plenty would have jumped at economic opportunities to relocate to Paris/London/Berlin, have to figure it was harvested for prizefighter stock back in those wild, racisr days of European hegemony.
Meaning what Calzaghe and Ward did? Absolutely. Bika, while the least fundamentally skilled of this group, is probably the biggest nightmare to face h2h (both as stylistic puzzle and just in terms of the amount of pain he inflicts - both legally and illegally) and both SOG and the Dragon saw their way through his craziness with aplomb. It rightfully elevated both their standings more than it should have just based on Bika's resume or ringcraft.
Povetkin? It was even on the cards as of the round before the stoppage. Might be Povetkin's hardest earned win outside Chambers (and even there he probably wasn't pissing blood for as long after Chambers, that was more of a fencing duel with jabs)
Interestingly, from the broader spectrum of combat sport's, the famous (or rather infamous) Sokoudjo from kickboxing and MMA, is a native of the République du Cameroun. He actually wanted to be a boxer originally but his parents forbade it on the grounds it was "too violent", pushing him to be a judoka instead. Lo and behold in the end he still ended up getting brutally KTFO more than a dozen times.
I dunno...he spent the better part of a decade (spanning most of the back half of the K2 era) as the consensus #2 HW on the planet, only lost to #1 ...tons of solid wins...
He was proven to be such a far second that I can't see him as much more than a footnote in Wlads chapter.
Yeah and funnily enough used his hands and even feet more than his Judo base.. Sometimes to his own success, but often to his determent like against Kharitonov a few weeks ago.. He had his moment back in the day after reeling off upset KO wins over Nog and Arona, but ultimately proved to be a 'flash in the plan' He probably had the talent to be more consistent, but as many who suffer setbacks tend to do he quickly developed a journeyman's mentality. Still dangerous to this day though....
He too wanted to pursue boxing initially and faced reluctance from his family. https://en.wikipedia.org/wiki/Francis_Ngannou#Background
There's nobody in the modern era to even give an honorable mention shout. Olivier Lontchi, maybe? ...and he did very little before getting squashed by primed out JuanMa López and Mikey Garcia in consecutive mismatches his first couple of times stepping up in class for a taste of something beyond prospect kibbles. (never posting another win again, with a failed comeback attempt in 2013 vs. middling regional attraction Tyler Asselstine)