Been pondering questions such as how long does it take to walk across a kingdom (assuming good roads), and how much of the kingdom is covered with forests where witches and trolls and bandits and dragons. Some of those kingdoms seem distinctly small, given that walking from one to another is not a problem. On the other hand -- the tales may say of the journey, "Speedily a tale is spun, with less speed a deed is done."
And if they are that small, there's economic questions. If you have a kingdom you can walk across in three or four days, how many servants can you afford at the castle?