Different worlds indeed. Here most people know better than to tow with a little SUV. What I've seen being towed in Europe, and especially in England, by small vehicles scared me.
I once bought a tractor dumptrailer. Borrowed my neighbours SUV because it is legal to tow 3500kg. But never again, its a short wheelbase with soft suspension, we didnt drive faster than 70km before the tail began to wag the dog. I have pulled heavier loads with my V70 which has a longer wheelbase and a more advanced suspension (rear axle rollbars and better Nivomat shocks that pump themself up after a few bumps to restore ride height) at much higher speeds.
So i'd rather be illegal and safe, than legal and holding up traffic because i'm a hazard to other traffic if i got up to the speed limit...
Guys who had a short wheelbase Nissan Patrol (think alike a Jap Bronco) say the same thing, when they changed it to s long wheelbase Mercedes they towed much easier.
Then again, I'm one of those who refuse to tow with a 1/2-ton pickup, feeling that they're too light and short, and also because the mechanical bits underneath are generally on the tiny side. Including the brakes.
What we found is that a standard half ton, has a rear suspension tuned for comfort, geared towards the soccer mom who puts the sweaty gear in the back, or the weekend offroader who wants soft, long travel suspension to keep all fours in contact with the ground in difficult terrain.
What our customer found is that If you really want to tow with it, you need suspension upgrades on your half ton.
In America they only sell the Sprinter 2500 (3.5 ton GVW Sprinter 319 in Europe) and Sprinter 3500 (5 ton Sprinter 519 in Europe)
We also get the Sprinter 219 (which translates to Sprinter 1500 if it was sold in America) but that is a useless vehicle, with its single leaf suspension. Its too soft in the back to keep a trailer straight, and if you buy it as an extra long, extra wide van, its just dangerous to drive in heavy crosswinds.
For 5th wheel tractors we sometimes sold the 5 ton Sprinter with full air suspension. We put the 3 leaf suspension that came off it, under a 3.5 ton Sprinter which came off factory with only two... Boy that made a difference in body roll when pulling a 36ft curtainsider !
If something happens to my Ram 3500 (14,000 lb. GVWR) I'll most likely order a 4500, or maybe a 5500. And probably with the 204" wheelbase.
Wheelbase and suspension make a tow vehicle. Even if you dont utilize the load capacity of the heavy rear suspension, you need its stiffness to reduce body roll and make it tow smooth by preventing the movements of the trailer being transferred to the tow vehicle
The problem with 4x4 trucks is that you want a low roll stiffness to follow the contour of heavy terrain, yet you need stiff suspension to stop the movements of the trailer being transferred to the tow vehicle. You cant have both..