Those pronunciations are not arbitrary. Consistent spelling was not always important to English writers, so some of that may be arbitrary. The words though have diverse etymologies reflecting multiculturalism born from brutal imperialism spanning centuries. It is often a system of language evolved from violent colonial expansion. Every weird word and spelling that breaks the rule has a story. It may not be a perfectly ordered system because it lives and breathes while some parts grow and others whither and die, but nothing about it arbitrary. Maybe I've been listening to too much of The Allusionist podcast.