Recently saw this video and thought it was worth sharing.
The video did mention an unofficial rule (in Australia), that is apparently law here in CA. I had to make a donation to local law enforcement for towing a 1500 Durango on my car hauler with my Jeep XJ. The issuing officer stated that it is illegal to tow a load that is heavier than the tow vehicle. I would look into the legalities, where you will be towing, and weight ratings of your rig.
One other thought regarding tow vehicle weight. While launching my 21' Hallett at an unusually steep launch ramp where sand and gravel had gotten kicked onto the dry ramp. The weight of my boat did pull my '83 Suburban around quiet a bit, causing the front tires to slide around like on ice. A few passengers and 4-low calmed that down.
I'd hate to be the guy who sinks his tow rig at the launch ramp, or worse yet, the guy who rolls his boat on the Interstate.