It may be correct that shorter trailers have less percentage of pin wt. It is true for the 2003 Komfort line for which I have the numbers.
Using unloaded wts:
22ft- is 5,546 and 602 = 10.8%
24ft- is 6,772 and 999 = 14.8%
26ft- is 7,706 and 1,415= 18.4%
29ft- is 10,206 and 2,676= 26.2%
You may have a different percentage of pin weight loaded vs unloaded depending on where the load goes--forwards, over the wheels, or behind the trailer wheels.
As loaded on the scales our 26er comes out as 9,800 and 1,900 for 19.4% vs the unloaded spec 18.4% because most of the cargo goes forward in the basement cargo bay and under the bed up front.