i think for an art degree it is more crucial you learn the stuff and know how and when apply it. e.g. linguistic, philosophy. These area/techniques requires a person to use them frequently to get the most out of it. I think in the end when you pass all your degree requirements and get your degree they wouldn't really care about the marks anymore, esp arts degree. Able to demonstrate afterwards is more important.
imo uni marks are important when you want a transfer or applying jobs which are academic driven (e.g. a maths professor, leading-edge scientific position). otherwise experience speaks for itself after you earn your degree.
enjoy.