I was talking to my friend about them, and neither of us really could figure out how the Rhodesians were as successful as they were against Mugabe and Nkomo's forces.
You may be interested in this previous answer about the romanticization of Rhodesia in the English-speaking world as well as this post about the Bush War to look at the larger strategic picture. We also have Two podcast episodes on the history of Zimbabwe. This answer discusses the contemporary place of Rhodesian nostalgia in modern politics.