I recently helped a friend weigh his DP at a local scale where there is room to get off to one side. We first weighed each axle and then by moving over, the RF and RR. Next we turned the MH around and weighed the LR and LR the same distance off the scale... which is 2-3" inches lower than the scale. The sum of these individual tire weights were close to 1000 lbs less than the original axle weight, but they do give a close approximation of how well the MH is balanced side to side. It was a 05 Monaco Diplomat and the front was within 50 lbs and the rear within 100 lbs ofbeing balanced with full fuel, water and load ready to leave on vacation.
On a good certified truck scale the four leg analogy above is not correct. The error will be less than 50 lbs.