Interestingly China in Africa has been more commercial (not that "free" long term loans don't have a down side, and bribing "officials' to condone the sale of generational farming lands, etc. isn't a bad thing) than military - but where China has used mercenary forces .. it's most often been outsourced to US PMCs (Private Military Contractors)

eg. In the Congo https://friendsofthecongo.org/erik-prince-in-congo-transnati... and elsewhere.