For someone who asks "but what was aragorn's tax policy", GRRM isn't very concerned with understanding how political power works, even in feudal societies.

?? He wrote it that way, he wrote the downfall and the infighting and all that coming as a result of the lacking political power. If he didn't understand how political power worked, the civil wars and coups and infighting would all have been results of some idealistic libshit instead.