I appreciate this essay doesn't answer the question directly as asked, but I feel it is a useful exploration of why there is generally so little (relatively weak) criticism of Wagner from African nations.
African nations were mostly aligned with the USSR during the Cold War, primarily due to the latter's willingness to assist said nations in their various struggles to liberate themselves from Western colonialist overlords. There is also significant overlap between the African concept of ubuntu and the socialist/communist worldview that the USSR espoused, giving the very different African and Caucasian cultures a shared baseline from which to build a rapport and working relationship - one that could never exist between those same African peoples and their exploitative capitalist masters from the West.
While the USSR's assistance in these liberation struggles cannot honestly be termed altruistic (as opposed to the continent being merely another front in the Cold War), the fact of the matter is that the USSR (and China) was the only party willing to aid the African nations in their most desperate hours. When someone is offering you a hand to save you from drowning, you don't ask too hard why they're doing so.
The end result is that after liberation from colonialism, much of the population of these African nations retains a deep sense of gratitude towards the USSR. The end of the Cold War, the collapse of the USSR and its devolution back to plain old Russia did nothing to diminish this deeply-ingrained goodwill - indeed many of these nations perceived the USSR's demise due to it making sacrifices to assist them in their liberation struggle, further enhancing feelings of kinship. In contrast the West was viewed as responsible for the USSR's fall and given its colonialist past - and the number of Africans alive who had experienced brutality at the hands of colonial powers - sympathy for the USSR was further buoyed.
Then we have the unforeseen consequences of the liberation of African nations. Many of these, much like nations in the Middle East, had their borders arbitrarily defined by Western powers in ways that failed to take into account the ethnic distributions of tribes who actually lived in those areas. In others, certain tribes collaborated with the Western oppressors during the colonialist era. The end result was that for many nations, with the end of colonialism came the beginning of civil wars.
On top of that we have to add the nature of the leaders who came to power in the post-colonial era. Many of these were men who had risen to leadership on the back of their qualities in fighting the colonialists and preventing dissent amongst the populace... qualities that generally make for poor peacetime leadership, the result being further civil strife. Even more unfortunately, many of these new leaders discovered the old adage that absolute power corrupts absolutely, with the result that once they had gained leadership of a nation they were loathe to relinquish it for annoying reasons like "democracy".
Finally, we layer onto this the fact that Africa is incredibly wealthy in natural resources and you can begin to appreciate the full scope of the problem: nations racked by civil wars, with leaders of all levels of power desperately trying to cling to that power, controlling vast wealth but nominally supported by personnel whose loyalty is based on ethnic grounds and could change tomorrow. As one of those leaders, then, who do you turn to when you need a reliable military force whose only motivation is wealth?
How about your old "friend" Russia, now broke but still with one of the largest standing militaries in the world - a standing military where one grunt is worth a dozen local fighters, and far more loyal? Surely Russia will be willing to assist these African leaders, in exchange for some of the wealth extracted from their lands? After all, that wealth is useless to that leader if they're dead, so if giving some of it to your old "friend" is the price of keeping your power and your head, that's a no-brainer, right?
The cash-poor Russia thought this was a swell idea too, but there was a problem: sending a bunch of official Russian military over to Africa would quite conceivably draw some ire from the (now much more powerful) West, as well as the Africans who still remember colonialism. How to overcome that little hurdle? Well, by creating a nominally "private" military company and unofficially putting some of your military assets under its control, in exchange for it going to Africa and doing some dirty work... while unofficially sharing the spoils of that dirty work with the Russian state. Neither the West nor the African nations would look too hard at this piece of smoke and mirrors - especially when the former was trying to avoid getting itself embroiled in African affairs, and the latter's goodwill towards ye olde USSR mostly remained.
The end result is that the private military company Wagner was formed in Russia, and it began providing "security services" to pretty much any African leader of any description or legitimacy who was able and willing to pay. In many cases Wagner's application of Russian state know-how and resources allowed them to more efficiently exploit the resources that they had access to, enriching both themselves and the leader they were propping up... allowing that leader to hire more Wagner mercenaries, take control of new territory instead of just holding their existing fief, and further enrich both parties.
Other African leaders, especially the more legitimate and democratic ones, have understood this ingress of Wagner for the dangerous and destabilising force that it is. Unfortunately for them, their nations are in much the same boat as most of Wagner's enemies: "protected" by ineffective armies of questionable loyalty. For such a nation, speaking out against Russia could conceivably invite a visit by Wagner.
Finally, there is one final legacy of the USSR that ties most African states to Russia, and that is materiel. Most African armies are trained in and equipped with Russian weapons and vehicles, which means that if they should insult Russia in any way, they very conceivably could be cut off from a supply of arms that they might need if, I dunno, a hostile PMC decides to invade them for no apparent reason.
In short, there are many reasons why African nations are generally hesitant to criticise Russia: a big dollop of historically positive sentiment from the populace, add a lot of conflict, plus a healthy dose of fear from their leadership, and a sprinkling of realpolitik around arms shipments. Russia's recent withdrawal from the grain deal - a deal critical to ensuring that large numbers of those nations' people don't starve - has drawn some stronger words, and if this comes to pass those words may become stronger still... but it's still unlikely that we'll see much outright condemnation of any of Russia's actions from most African nations, except for the few (like Kenya) that have been traditionally closer to the West and democracy.
