Accurate tongue weight is critical for safe towing, particularly with a toy hauler. Every manufacturer and salesman wants to quote you a completely BS number known as "Dry Tongue Weight". Not once in the history of the world has that number ever been even remotely accurate. :S
Take the GVWR of any trailer and compute 13% to 15% of that number, toy haulers need to be nearer to 15%, and you will get reasonably close to a real world tongue weight. No, not everyone loads to the GVWR but TW, especially in a toy hauler, is so important that being on the conservative side of the equation is not a bad thing.
Any salesman that quotes you "Dry" anything weights is NOT your friend, thinks you are an imbecile and does not deserve your business much less your trust. So how do I really feel? :R
As Always.... Opinions and YMMV. :C