Your front and back axles do different jobs, so I don't think matching front to rear is required or even desirable. Now 2 tires running side by each need to be the same height or the short one will wear real fast. And if the tires on the ends of a drive axle are of different heights, it will cause extra wear in the differential. Mis-matched steering tires? Some trucks you only notice when inspecting, others it can make it feel bad.
Now when I say the tires need to be the same height, I'm talking about how high they hold the axle when aired up and under load. Most times I wrap a tape measure around, measure the circumference, to match before I put them on.
BTW, I have no RV experience, but have ran trucks millions of miles.