I find it interesting that the truck argument rears its ugly head again.
I once had a 19 foot TT. I towed it with either a Dodge 3/4 ton flatbed with Load Range E tires, or a Jeep Wagoneer with P rated tires, or a Ford E150 Club Wagon with P rated tires. The Dodge had a 400 V8, the Ford had a 351, and the Wagoneer had an AMC 360. I had to use a WD hitch on the Wagoneer to keep the back bumper off the ground. I did not use the WD hitch on the others.
I towed that trailer on 2 track dirt roads in the mountains, over mountain passes on 2 lane highways, and on the freeways(what few we have here).
I did not use any sway control of any kind.
Never had an accident, never had sway, barely had any wind wander. The trailer was rock solid behind all three tow vehicles!
(sigh)Just lucky, I guess. Proper loading couldn't have had anything to do with it, right?