We had a 29 foot Tioga class C with the Ford 460 engine. I wanted to tow the Jeep Wrangler Rubicon Unlimited I had at the time. The hitch was rated at 3500 lbs. capacity, and the towbar I had was rated at 5000 lbs.
I had the hitch reinforced by a highly qualified welder, and he inspected the frame extensions and said I was good to go. I guess he was right, because I towed that slightly modified Jeep up and down mountains, across the Continental Divide, over rough back country roads and on the freeway at 65 MPH for a couple of years. Nothing bent, nothing broke, nobody was injured or died. I have no idea what the Jeep weighed with all the extra iron (and the 30 gallon fuel tank) that was bolted on it. I didn't care, so I never weighed it.
IMO, success trumps the numbers every time.
Now, I have a Class A with the Ford V10, and tow the truck in my sig. with a 6000 lb. capacity towbar. It works.