Well, the Subsaharan wars were more relapses into anarchy than wars as we in the West understand such things. Of the millions who tragically died, most were poor tribal peoples caught up in anarchic situations. The Congo war was a perfect example. I quote from Marius' link:
"
The largest war in modern African history, it directly involved eight African nations, as well as about 25 armed groups. By 2008 the war and its aftermath had killed 5.4 million people, mostly from disease and starvation,[4] making the Second Congo War the deadliest conflict worldwide since World War II.[5] Millions more were displaced from their homes or sought asylum in neighboring countries.[6]
Despite a formal end to the war in July 2003 and an agreement by the former belligerents to create a government of national unity, 1,000 people died daily in 2004 from easily preventable cases of malnutrition and disease.[7]"
It was anyway mostly a civil war, certainly not as I specified a war waged outside the Congo borders.
The Eritrean/Etheopian war was of course not subsaharan. No one doubts the abilities of North and horn of Africa nations to engage in wars.