How does arthur become king? how is this in keeping with the medieval zeitgeist? plz

In Monty Python and the Holy Grail, the Pythons presented a sub-Roman world populated by medieval filth and ignorance, but also characters mythological (King Arthur, the Legendary Beast), quasi-historical (tribe leader Arthur), and anachronistic (Dennis, policemen).  I think that is the answer

When Amiens had sung this song, he had compared nature and man. He had described Man as an unkind and treacherous. He believed that humans used friendship to stabbed and conquer others behind their back. He believed that Nature is more amiable although it can be challenging and harsh. He thought that Nature would never harm anyone.