My Ram 5500 is typically about 11,500 lbs before I add the camper and trailer to it. Roughly 600 lbs of this weight are my battery banks that I carry in the lower enclosed boxes. The Ram has a steel 9' deck and six steel boxes plus goose neck, double receiver and extension that all are counted in this weight.
My Host Mammoth is over 4700 lbs dry and closer to 6000 lbs when filled and stocked. 500 lbs is easily just in water.
My enclosed trailer is 3500 lbs empty and typically loaded between 6000-8000 lbs with 1000 lbs of tongue weight added to the rear truck axle even when using a WDH on my 42" extension.
My vehicle GVW is 17,500-18,500 lbs and GCW is 17,500-25,500 lbs depending on the configured setup at the time. All these actual weights are within the printed ratings, but still pretty close to maximum even in a Class 5 truck.