Your entire elaborate argument is based on a false premise.
As I said, the road damage is exponential with the weight. It is proportional to the axle weight to the fourth power.
Fuel economy is roughly linear with weight, or even less than linear (big rigs get much better MPG per ton than smaller vehicles). Therefore, fuel taxes don't begin to recover the extra costs of heavier vehicles.
Who has made the stupidest argument you've ever heard now? You might look in the mirror.