I think we got two threads going here..lol
How are you estimating your load range? Tongue weight is not that much typically and rarely does towing have much to do with load range or tires. Now hauling....truck stuffed full of 1000s of lbs....Certainly needs higher load range tires, although you would be amazed hoe many people overload vehicles and tires with no noticeable issues....
I know many people say err to the side of higher capacity bu how much extra weight are you really putting on your tires....and only mostly on the rear ones?? You could scale it. But an average truck is WAY below the limit of the load capacity of a tire and D and E are even higher.
I would have to look at the numbers.