This is gonna be my final closing arguement for this topic, I'm not going to indulge my further into something to which you have tons of information to, also refering to the links you have put in.
First - your stable population refers to the Orange river, there is No mentioning of Augrabies National Park, so part of this river system are along National Park.
The one block on the right hand side as indicated on the map:DSC02790
, on Flickr
Also to say that 55000 ha is large enough to support this amount of leopards with out even thinking of the habitat requirements is a bit harch.Why do you think they mention the Orange river?I will tell you because it is perfect habitat requirements,thickets of vegetation and so on. As well in the Park there is a band of +- 100km of rocky ridges with a wide of 5km extending from the restcamp area to the end of the park, certainly not the whole 55000ha.
And this is what the Cybertracker data shown as all these sightings lies in this band.
If you take simple mathematics as you was mentioning the Park won't be able to sustain 20 or more leopards together with their territories.
The data that you have given is for the Orange river and not for the Park,simple mathematics the average of 20 as a minimum for a stable population is for these three sections is 6.6, our leopard numbers are 5.
Malealea as you can see a simple monitoring method,also give results.
By the way I'm the field guide here studying towards a Conservation Diploma.