Well, we never aim to have a game surplus for profit as you say, and no we aren't maximising the few cash crops. Impala were fetching about 20 GBP last year and we could get noone to take them off, subsequently we had to sit and watch 200 die of starvation as the draught stressed bush was browsed bare. There is never a total stability believe me.
The levels of animals are maintained for the soul reason of protecting the whole environment for the benefit of all mammals, birds, insects trees and plants ect, the whole package. We do not take part in predator control, and they are a factor in carrying capacity for a farm.
I live in an area that forms part of the greater kruger park, the team that does our veld analysis and game counts also do the same thing for the Kruger national park. They then advise on carrying capacities.
I would think that they do not 'draw huge conclusions from insufficeint data' as they are highly esteemed experts on animal management.
Yes my farm is small but i would bet that there are smaller deer estates in the uK.
I was really only suggesting that the UK could look to other experts around the world who have a long history with these issues of animal management. So much research and countless studies have been done here and around the world that surely some of this work must be of use to the UK trying to sort out wether it does or doesn't have a problem with deer populations, in or outside deer estates.( i believe the issue also involves populations outside managed areas as well causing a whole other set of problems) and how they might deal with the problems.