Trying to learn the actual load on each "corner" of a motorhome is the BEST policy.
is a link to a worksheet that will help you learn the facts.
Class-C may be more balanced than Class-A but still can be hundreds of pounds out of balance side to side on an axle (Slides, location of generator , holding tanks etc).
Lacking corner weights I suggest a quick estimate of 45/55 % split side to side on each axle.
So once you have the numbers for each corner and you consult the charts for your tires. You will know the MINIMUM inflation for fronts (single loads) and rears (dual). Pay attention to the chart as some companies give the loads for each individual tire while others will give the load for the pair of duals. Dual position load capacity is always lower per tire than single position load capacity.
Using the heavier axle end number (or higher load end number if estimating) you now know the MINIMUM CIP setting for ALL tires on that axle.
I then suggest your set pressure to be the MINIMUM pressure + 10% .
F 5,000 R 10200
45/55 F 2250/2750 R 4490/ 5610 <corner loads
Tire loads F2250/2750 R 2245/2805
I would use the inflation for singles that supports AT LEAST 2750# and the inflation for duals that supports AT LEAST 2805# as my MINIMUM
My set pressure for all tires would be the MINIMUM +10%
Hope this clears things up.