If it were me I would start with the heaviest stuff first like the head and water/grey/black water tanks.
They will need to be located mostly on the driverside and nearer to the rear.. The driverside of the coach should weigh in 1000-2000+ pounds heavier than the pass side due to the water shed built into the roads makes the lower side right carry more weight.
So load up the high side.
A current dry weight on all axles and sides might be good to give yourself a baseline in order to keep things ballanced as you go...
Up till 2005 -2007? bluebird overloaded the front axles and had to rerate the front of the RV so no additional storage load would be allowed 4 to 2 people 1/4 fresh water... move the heavy stuff in back....
What was actually needed was a heavier rated front axle.
Many complained that just a well stocked pantry would throw the front over the limit...