Actually camp-n-family is right on the mark with TT and TH being like apples and oranges - they are quite different in how they are designed. Traditional trailers are designed to be mostly balanced with approximately 10-12% tongue weight empty. Toy Haulers on the other hand are designed with substantially more tongue weight empty around 20%. They do this on purpose to offset the massive amount of weight that will be placed - often times behind the rear axles of the trailer.
That may not sound like a lot but you can't really tow around a TH properly without the toys in the back to balance out the load. The towing fundamentals stay the same with optimal towing around 13-15% tongue weight. Toy Haulers are more complicated to tow and balance properly and it requires a bit of forethought to place cargo appropriately.
I understand that THs are usually balanced differently to accomodate the loads in the rear and as such are normally tongue heavy and handle differently than a conventional TT but from the weights listed above this doesn't appear to be the case. I'm not familiar with the TH mentioned but if delivered weights are close to the listed dry weights, 4k with a tongue of 450lbs (11%), it could easily be loaded to maintain proper balance and tongue weight. For example if it is loaded with 500lbs worth of options and 2k worth of stuff would put it around 6500lbs loaded. A tongue weight of 15% is under 1k and should be achievable even for a toy hauler.
The only way to know for sure is to load and weigh it. Don't discount todays 1/2 ton trucks until you do the math. It may work just fine, it may not, but you don't need a dually for everything.
