Thomas, I read what you were saying about 8 pages ago and I can promise you that I'm not sounding like you were (and largely still are).
If it weren't for the tongue weight bearing down on the rear axle, there wouldn't BE any excess load that you'd want to remove from the rear axle. The tongue weight is the source.
The ONLY reason the tongue weight isn't required in Ron's equations is because of his assumption of the spring bar tension being 1000 pounds each. If you didn't have adequate tongue weight and you had really light vehicles (ALSO not in the equations), that 2000 pounds in your WD system would turn your TV/TT combination into a pair of scissors.
