Fridge Horror: Congratulations, Arthur! You're a child king in Medieval England! You're basically surrounded by hostile nations, the country's been in a leaderless quagmire of indecision for most of your lifetime, your trusted advisor flies into a rage and ditches you at the very idea of you being involved in combat, and your only preparation for all this has been the dubious lessons of being turned into amusing animals. ... Well, good luck! (Thankfully, you're a Disney monarch, so you basically just get a vague, implied Happily Ever After. At least until they decide to make Sword In The Stone 2.)
Fridge Logic: The entire movie has been pushing the idea that being educated will get you ahead in life. This culminates in the finale, where Arthur... pulls a sword out of a stone... which has nothing to do with education.