Access course and one A level

I’m planning on studying an A level in literature online this year, before doing an access course next year.
I think doing the A level will help me decide if I truly want to go to university at 21, but would it also give me a better chance at getting into a Russell group?

An Access Diploma is designed to take you from L2 (GCSE) to L3 (A levels) in 1 year. If you're taking A levels then an Access Diploma would normally not be a suitable qualification - you'd be better off taking 2 or 3 A levels instead. Mixing and matching like this isn't ideal.

The information for access to HE requirements on Oxford uni’s site states it’s better to have one or two A levels alongside it if possible. I’m not aiming for Oxford at all, but surely if it’s good enough for them, it’s good enough for others?