I'm not sure that Executive Outcomes (EO) or any PMC would have made much difference in the Rhodesian civil war (1960s to 1980). The Rhodesians (depending on the stats) had a 1:17 or 1:43 kill ratio against the Marxist rebels. An incredible kill ratio. The Rhodesians had mercenaries (a couple thousand). Yet they still lost.

The SADF guys who formed EO are really a direct descendent of the Rhodesian military forces in many ways. After the Rhodesians lost, many of them joined the South African Defense Forces (SADF). They influenced the SADF special forces concepts, counter-insurgency and warfare tactics. South Africa’s counter-insurgency policy wasn’t exactly successful either. Probably because they didn’t learn anything from the failure of the Rhodesian experience. They continued to use the failed practices that their Rhodesian brothers taught them.

If EO was around and had to fight in the Rhodesian war, I highly doubt they would have made any difference against the Marxist rebels. Primarily because they were/are a reflection of the same Rhodesian forces that fought and lost in that war. Racking up a high kill ratio doesn’t cut it in counter-insurgency. Ian Beckett succinctly described the Rhodesian’s main problem:

it has been suggested that the apolitical nature of the Rhodesian armed forces prevented them from seriously coming to terms with the political aspects of guerrilla insurgency. There was never any real attempt at political indoctrination or instruction within the Rhodesian armed forces and to the end of the war guerrilla insurgency tended to be regarded as a military rather than a political problem to which military solutions alone should be applied.

http://members.tripod.com/selousscou...79%20part1.htm

I think the same could be said of the SADF and military oriented solutions to the counter-insurgency strategy of South Africa.

Check this website for articles and other great info on the Rhodesian civil war.

http://members.tripod.com/selousscou...l_overview.htm

These articles below detail some of the ways Rhodesian forces influenced the SADF.

O'Brien, Kevin A. "The Use of Assassination as a Tool of State Policy: South Africa's Counter-Revolutionary Strategy 1979-1992." (Parts I and II) Terrorism and Political Violence 10, no. 3 (Summer 1998): 86-105 and 13, no. 2 (Spring 2001): 107-142.

'Brien, Kevin A. "Counter-Intelligence for Counter-Revolutionary Warfare: The South African Police Security Branch, 1979-1990." Intelligence and National Security 16, no. 3 (Autumn 2001): 27-59.