I don't know how you model the physics, but in that last video the RRs seem to land from flight rear first quite alot. From my experience of flying Land Rovers, and I have a fair bit, with any decent length of flight you will most often land nose first. My Discovery flies quite level generally, but if you jump a long way it will still tend nose first!
Might be worth checking out some Hillrally videos. Obviously the loading and damping of Camel Trophy Range Rovers would have an immense effect!