This is an excellent article, but one point they missed is the Total Frontal Area of the truck and trailer, which determines the wind resistance going down the road.
As pointed out in the article, truck makers like to get their "pull" (towing) weights as high as possible for bragging rights. One thing they overlooked is usually this is determined while towing something like a flatbed trailer carrying a concrete block or a utility trailer that totally fits inside the tow vehicle's slip stream.
RV trailers aren't made that way, they're taller and wider than the tow vehicle which increases their wind resistance. If you've loaded the truck with the heaviest RV trailer it claims it can tow, you will be operating at the minimum acceptable performance levels and may run short of power driving into a headwind going down the road.
Vacation towing is supposed to be a pleasant activity, not a white knuckle slugfest. An RV trailer's extra wind resistance, along with stability and having more than the absolute minimum performance is why experienced RVers like to keep their trailer weight at or below 80% of the vehicle's weight limits. That extra 20% capacity makes a good buffer for headwinds, emergency maneuvers, etc.