Forgive me if this seems a bit arrogant, but I reckon it's fairly easy to score band 5 in English Standard. It's all about targeting the right thing.
A lot of people in Standard do not know a lot of basic jargon that is extremely relevent in their responses such as context and audience reaction.
I personally found it quite shocking that many people I knew who scored band 4 did not know the fundamental relationship between the composer's context, the composer's purpose, literary devices, the effect of these devices on the audience, and how this effect attempts to orientate the audience's perspective of a certain idea or context. So to be at band 5 level, typically means that you need to understand these basic concepts in English under each module heading.
Another thing I noticed with those who scored band 4 is that they are often confused about the requirements of the module and many didn't even realise that you have to approach your essays/responses
differently with each module.
So, Module A - Experience Through Language, means you have to examine how composers use particular aspects (either narrative, dialogue or image) to allow the audience to experience the their perspective(s).
Module B - Close Study of Text, means you have to engage with your text very closely and thoroughly, and examine how several features like context, certain literary devices, medium, genre, themes/messages etc, make up the distinctive (unique) qualities of the text.
Module C - Texts and Society, means you have to relate texts with their context and how composers attempt to represent an aspect of society in those texts.
Many band 4 students do not know the above and often blindly answer a question by regurgitating memorised essays word for word or writing down irrelevent ideas (e.g. tell the story rather than analyse it).
So basically, it's not about the time you spend on English, it's about whether you explicitly understand the concepts or not (and similarly applies for most other subjects). I think the raw mark to get 80 last year was about 70/105, so that'll give you something to aim for.
I for one, spent the least weighting of my study on English and still managed a mid to high band 5. I'm sure you can as well....