Just a couple of things to note. In Botswana all registered game private farms are required to be enclose by high fence. Only govt concession areas are exempt from the high fence requirement. The govt concession areas are primarily for elephant, buffalo and leopard on limited quota. There normally is very little PG included in the concession quotas.
When driving/touring in Bots last year, we did basically what I call the "great circle tour" Started out in Gaborone, and took the Trans-Kalahari Highway NW up to Ghanzi, Maun, Kasane and then back down SE via Nata, Francistown, Mahalapye and back to Gabs. The major thing we noticed along the entire drive was the total lack of any game species, not even warthogs, along the roads S of Ghanzi and then again S of Nata. All we'd see were goats, donkeys and a few cows. N of those cites was pretty much all National parks. In this part it was game and elephants galore. The lands outside of these areas could be private regular farms or govt lands. The reason given to us by MULTIPLE people we talked to about the lack of game along the roads was the same - poaching. Did we see ALL of Botswana? No. However, in the 30-days driving around, and talking to a lot of people and seeing a LOT of National Parks and asking the same questions and getting the same answers all the time........... When driving around most of Namibia, you'll see game along from the roads.
I've hunted Namibia a LOT and the Tuli block in the eastern side of Botswana several times. I've driven over and around most of Namibia and spent 30-day last year driving around Botswana. From what I have seen and experienced if you are after a 40"+ free range, fare chase gemsbok, your best bet is NW Namibia, S of the Etosha NP in the mountains between Outjo and Kamanjab. That area sees relatively little hunting pressure and produces several bulls in the 40"+ range every year.