Chelseaaaakane To reiterate what Huseyin said above, it is quite difficult to do well in Standard English with only roughly I think 1% of the candidates receiving a Band 6, of which I would assume most of those have exposed themselves to literature since they were young but decided to not take higher levels of English. I do Standard English myself and I slightly regret it however if you do more sciency-based courses which you want to focus on, then it'll be a way to gain slightly more time to work on those other subjects. However, although Standard English is the second lowest english course, there is still quite a bit of content and work to do, don't disregard this!
Just think a little wisely I guess about what you want to do, although I'd think it'd be quite disruptive going from Advanced to Standard nearly midway through, because you'll have to learn the texts your standard cohort would have done last term.