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Does anyone have any experience in this matter?
While I don't have experience towing with a Land Rover, I do have experience towing with other vehicles at or very near their maximum towed weight rating. It isn't something that I would recommend doing if alternatives are available. While your Overlander's listed factory dry weight may be 4,500 pounds, this would have been without options and options can increase that weight. For instance, my '64 Overlander has a factory empty (dry) weight of 3,930 pounds - - but with options, its empty (dry) weight is 4,440 pounds ((options include air conditioner, awnings (curbside, bathroom, and streetside bedroom), 10 gallon water heater, 40 pound Worthington Aluminum LP tanks, electric tongue jack, International Package, and 4-BAL stabilizing jacks)). When fully loaded for an extended vacation, the trailer typically weighs in at very near 6,100 pounds.
If you do a forums search on Land Rover, I think that you will discover at least one or two threads discussing towing considerations with this line of vehicles. I believe that there was something mentioned in at least one of the threads about the factory trailer towing specifications severely limiting tongue weight which could be an issue with an Overlander - - it will likely be in in excess of 600 pounds when the trailer is fully loaded for an extended trip - - I know that the tongue weight on my Overlander exceeds 700 pounds when it is loaded for the WBCCI International Rally and the events preceding and following the rally.
My previous tow vehicle, a 1995 Chevrolet K-1500 Z-71 Club Cab Pickup with 5.7 Liter V8 and 3.73 differential gearing struggled with the Overlander even in the modest hills of Southern Illinois. It nearly didn't make it through the Eisenhower Tunnel on I-70 - - the truck was down to less than 20 MPH in low at full-throttle. The truck had a 6,500 pound trailer tow rating.
One of the reasons that I limit my towing of the Overlander with the Cadillac, despite its large 8.2 Liter V8, is its factory trailer tow rating of 6,000 pounds - - it handles the trailer fine on flat highways, but begins to struggle when steeper hills are encountered. It does just fine with the 6.0 Metre Argosy Minuet with its gross weight of 3,200 pounds.
Good luck with your towing decisions!