Hi! I'm applying for an awkward combination as well (Biology and Film Studies), and as with A-levels, picking subjects you enjoy is always a good route to go down.
Have you looked in more depth at the universities that offer this course combination? Their course specifications will give you information on how a joint degree will work.
If you enjoy a course, there's no reason to not go for it. Joint degrees are popular options, complementary course or not. Just bear in mind you only have one personal statement to write, so consider how you can encompass both subjects in the one.