Perhaps this will help you understand better.
GVWR 6900 - 5384 Curb weight = 1516# cargo capacity. Problem is once you add family, fill the fuel tank, bed liner, bed cover, running boards and add some stuff to go camping with your truck will weigh around 6,000# (you can always weigh it at a truck stop to get the actual number. So GVWR of 6,900# - actual truck weight leaves maybe 900# (conservative) for the trailers hitch weight. Now if your truck loaded with family, fuel and camping gear weighs less than 6,000# your capacity will go up. So to get an accurate capacity you really need to weigh your truck.
While your truck claims a 10,200# tow rating that's with a stripped truck, 150# driver and a easy to pull trailer with a light tongue weight, not a box called a travel trailer (TT). The TT will have a tongue or hitch weight of 13-15% of the loaded trailer weigh. Say your WDH weighs 100# you have about 800# left for the trailers tongue weight. 800#/15% = 5,333# loaded trailer max.
Most people add 500-1000# of stuff to a TT so if you add 1,000# to the dry weight of the trailer you are looking you'll have an idea of what you are looking at. So that leaves you a dry trailer weight around 4,000#.
Hope that helps you find the "Holy Grail". Hope you can see how to run the numbers to find a TT within the limits of your truck.
Good luck and enjoy.