I am happy to hear you have elected not to use the Range Rover to tow this vehicle.
I also reviewed the closed thread from 2014. Ironically, the person in that thread asked almost the same question as you, and simply wasn't happy with the questions.
I LOVE land rovers. See my user name: Nashrover (on other boards known as nashvillerover). I have owned or driven every model land rover ever made (at least one of each), including series trucks, Range Rover Classics to MKIII's, Disco I- LR4, and when I got the airstream, I sold my last land rover and purchased a Ford F250. When traveling with my family, safety and reliability is paramount. When you own a land rover, you understand that the lack of reliability comes with it. Even with my LR3 (the most reliable I ever owned), I had challenges, like an alarm system that had a mind of its own! But pair that truck with a trailer that pushes the upper limits of its tow capability, and you are asking for trouble. Will it tow it? Yes. Will it tow it with reliability and safety? Maybe. Is it worth the risk 'because you already have the truck'? NO!
In the end, people who are Land Rover people are passionate about the brand— as passionate as Airstream people are about Airstreams. But, I have known many who have argued the merits of Land Rovers, who after some cataclysmic failure, now would never own another. My last experience was this past year with a 2010 Range Rover MKIII. Transmission failed. $14,700 to replace the transmission (I have the receipt to prove it). Thankfully, having owned over 30 land rovers won me a good will warranty on the tranny through Land Rover North America. And what did I do? Immediately traded the truck for the F250.
I still love the brand, but just don't own one anymore. If I ever buy another, I always do so knowing the risk.
Good luck with whatever you decide to do.
2015 25' Eddie Bauer
2015 F250 TV-Petrol