The brochure tow ratings do not show ratings for the heavily optioned models. Most ratings are for cab style/bed length/wheelbase, and drive train, on basic optioned trucks. When TT tow rating is given, it is often limited by the receiver capacity, which has gone up in recent years. For FW towing, the numbers showing are similar, but not limited by receiver. A FW places most wt on the rear axle, so your axle rating/tire rating is the limiting number.
If you weigh your truck only, ready to camp, full fuel, and passengers, getting separate axle wts, you will see what is left for pin wt on your rear axle. All FWs are not the same either, as to gross wt/pin wt. One FW weighing 15,900 can have a heavier pin than another. A FW weighing 15,900 is going to have enough pin wt to be near your RAWR, depending how loaded, and what else is in bed of truck.
Jerry