You are right!
However, in a sense you are wrong -- My full-sized 82 Dodge D150 truck had a tow capacity of only 2,000 lbs and for my first three years of full-timing I was ignorantly pulling a Jayco 16' that had to have weighed about 2,400 lbs with my gear in it, plus a lot of extra stuf in the truck bed.
I believe the limit on the truck was the small manual clutch -- The engine was the venerable Slant-Six, but even with the 318 V8, the limit was still 2K -- With the V8 and an auto trans the limit became 3.5K.
I had to have several clutch jobs done, plus replace the main bearings -- When I got rid of the truck, it had a blown head gasket and one of the piston rods was very worn and making a lot of noise -- The truck only had 215K miles on it -- Had I not been towing, esp over the limit, I would have expected to get 300K and more out of that engine...
Also, on a wet gravel road in BC, I had the trailer slide out and yank the truck like you wouldn't believe (1,700 vs 4,500 lbs!) -- I realized that I had a lot of weight
in the truck -- So, I moved tools and heavy stuf as far forward as possible, including putting the spare tire on front of truck -- I shortened my overhang by four inches by moving receiver hitch and by shortening ball mount bar -- All became noticeably more stable.
Think about what it means to put a tow vehicle that has a shorter wheelbase and is lighter in front of a 13' Egg on a wet curved gravel road (And I was doing LESS than the speed limit at the time).
Now I have a so-called "small" truck, a '98 Ranger -- It is rated to tow almost three times as much as the Full-sized Truck -- Has a longer wheelbase, bigger 6-cylinder engine with better fuel and ignition system, bigger rear differential, same diff gear ratio but lower gears in transmission and weighs almost as much.
The Devil is indeed in the details...
BTW, the reason I posted about WDH, air springs, etc., was for general information and not for the Rondo -- And Brian B-P informed me that the Owner's Manuals for the CA and US versions do differ in towing capacity, although we don't know why.