Have interviewed hundreds of people in my various careers (big 4, banking, IT) and generally applicants are from all over the world, so people compete against MIT, Harvard etc.
At that level of competition, Russell Group is essential, and traditional subjects are very much preferred (not essential, but handicap you slightly in that it raises a ? In the mind of interviewer). Some vocational subjects you might think are good ones are not looked on that highly, even if from a good uni. These include accounting, business studies and stuff like marketing and HR. having them as courses within an economic degree is of course fine.
As a recruiter now for my own company I'm less snobby but would say that if you are not going for a russell/'good' uni, you need at least a traditional subject, or a first (I can be won over by passion & flair). A 2.2 from a little-known uni in a non traditional subject is, IMVHO, not of great value career-wise.
If you are looking at choice between two traditional subjects at a good uni, then go for the one that floats their boat most.