I knew, and used to fly with, an ex ZAF Mig pilot. He had been trained both in the UK and Russia and was a very high calibre pilot. He also happened to be the first Zambian pilot to break the sound barrier.
He was at Mumbwa Airbase that day and was itching to get airborne, but the directive from Kenneth Kaunda was to stay on the ground.
A Mig 21 in the hands of a competent and committed pilot is a potent force, and I suspect a few less Canberras and Hunters would have been transiting back across the border home!
The fact remains, although it was an impressive and daring raid, still it was carried out in the face of ZERO opposition, and so I'm still surprised the Rhodesians are held in such awe!