I agree with Mowog, if in doubt don't stuff around just get a Mitch Hitch and forget using the questionable OEM hitch.

A badly set up WDH often does cause all sorts of problems as well and most people have little idea on how to use them, they just crank them up as hard as possible.

The new Jeep Grand Cherokee which can be optioned up to have a similar gas / lift suspension and Terrain Response system to a D3/4 is now two years down the track required by JEEP to be used with a WDH when towing anything over 2.2 ton from memory and the Jeep has an alloy chassis, not a steel chassis like a D3/4.

Do date I have not heard of any failures on them and the grey nomad brigade that are buying them in droves would be whinging very loudly if there was even one failure while towing. My uneducated guess is it is the daft LR hitch if anything.

I'd guess if the Jeep can get away with a WDH then maybe it is possible to use one on the Disco as well, but personally I don't want to.