Our 63 Safari was much more susceptible to cross-winds and 18 wheelers than our Classic, using the same Reese WD with friction sway control.
The second axle improves tracking, a third axle even more.
Both single and dual need to be loaded correctly with tongue weight set appropriately.
But....I wouldn't go by those u-haul boxers, I think they would dance no matter who the partner.
"Sticks & stones can break your bones...and hail will dent your Airstream"
So when is this..."old enough to know better" supposed to kick in?