I agree that a full-sized pickup or SUV, even a "half ton" is too much for a gas-fueled Class C. Probably similar Class A, too. The diesel Class A's, whether pusher or FRED (FRont Engine Diesel) or Super C diesel, OK.
Our 31-ft C, signature, runs nearly 14000-pounds on the CAT Scales during a trip. Our midsize truck toad (base model Frontier) scales right at 4000. Yes, it tows it and Yes it stops it (Brake Buddy!). But I was able to equip my wife' Corolla with used parts for around $250 and shed about 1500. Of course it tows it and stops it, but it's just Better. For a gasser, my suggestion would be to try and keep the loaded toad under about 3500.