I have not hunted Mozambique yet but there is a significant difference in experience between wild hunts in concession areas and ranch hunts. A huge number of variables play into success on a hunt in a wild area. Time of year, previous rains, burning, lions, one week to next can be a very different hunt and different game numbers in area. A ranch hunt is much more predictable because of the fence and smaller area and most ranches have very few, if any, real predators. I think the question to ask yourself is what makes the trophy valuable to you. A wild buffalo to me is one that crossed boundaries, fought to breed, and was harassed by poachers and lions its whole life. Any degree of human management would start to diminish the trophy to me. The first buffalo I ever saw in RSA was getting chased down the highway along fence line. It was a trophy bull, I don’t know if it was an escape or a botched transport attempt. I also hunted plains game on property with only young bulls that were brought in and hunted a different property where two rouge bulls broke in from somewhere and I’ve driven past many breeding camps. The quality of buffalo hunting can vary a lot in South Africa. Many outfitters are not directly managing the areas they hunt there and sharing the areas with other outfitters. I’d ask clearly what self sustaining means and verify it if it’s an important consideration to you. The definition appears to have become very flexible and incorporated with game ranching industry there. There are good and bad concession areas as well, but game numbers can only increase naturally through good anti-poaching and adding water. Recognizing a quality concession area is more clear to me.
I’ve read and heard nothing but amazing things about Niassa, but from what I understand it is also one of the more expensive areas you can hunt. Have you considered looking into Zimbabwe? You could hunt some of the best areas there at same day rates as Niassa but significantly lower trophy fees on plains game and lower dip/pack costs and shipping home costs and no individual license fees. An area like Nyakasanga you will get wild Africa with no villages and see lions, elephants, buffalo most days. A community area like Dande with villages will be better pricing and a tougher hunt, but still nearly 100% success on buffalo. Zimbabwe might be a good compromise for you.
If you can afford and have the time, wild Africa really gives a better hunt in my opinion. Also the fenced areas will be there in 20 years. Many concession areas are under more pressure each day as the human population grows in Africa. I’d go while you can, they might not be there tomorrow.