While I was in both Rhodesia and South Africa, there were lots of units that were trained and led by white Mercs. In all instances if the mercs had actual combat experience the guerilla units of the ANC and others tended to run at the first shot of actual opposition.

Another example was in the Congo when the Mau Mau was destroyed by Mike O'hares mercs. Was even worse when they went up against a Battalion of Belgian paratroops. I spent time in Africa with veterans of both of those units. It was figured by even the most optimistic that a 20 to 1 ratio was EVEN odds!