Similar floorplans in two different model lines do not mean they should weigh the same. There will be trim and equipment differences between Freelander and Leprechaun, which might include things like foam seats vs steel-sprung seating, trim on cabinets, plumbing fixtures used, besides the usual differences in fabric patterns and colors available. I'm surprised the dry weights are so close.
There is an error in the Freelander numbers, current DOT standard is that Payload Capacity = GVWR - Dry Weight. The RV industry used to try to do a Cargo Carrying Capacity that separated out weights of fluids and persons that might be carried, now it is all part of Payload.
If these numbers come from and advertising brochure or web site, they are unlikely to match the numbers for any example actually manufactured, because the Dry Weight for this purpose is sum of components and estimate for materials from engineering documents, for an example with only "standard" equipment. The "Dry Weight" that now goes on the RV has to be measured on a scale, and is often different by a few pounds for identically equipped examples of the same model.
Tow ratings are usually determined by the rating of the towing equipment installed, or a tow rating from the chassis manufacturer, whichever is less. For current generation E-450 cutaway or E-350 with V-10 Ford's maximum tow rating is 10,000 pounds.
