This forum makes the mentality that you need 500HP to have 5000lb toad behind.
I remember that not farther than 20 years ago - lot of 80,000 lb semi-truck setups have been powered by 318 HP. They did crawl on long grades, but still made it to destination.
Than common picture in Europe is 3000 lb car towing 4000 lb travel trailer.
Why in US 20-30,000 lb motorhome should not pull 5000 lb toad?
Sure cheap hitch will need replacement or reinforcement and toad brakes will add safety, but I have seen it in Nebraska that 5000 lb pickup tow 7000lb equipment trailers with no brakes.
Not legal in California, but legal in flat states.