There's merit to both approaches, if you do poorly then picking a high scaling subject is irrelevant. Picking subjects to your strengths should ensure you perform well, but in some scenarios those subjects just may scale poorly. For most people, I don't think the scaling of a subject is going to be a limiting factor however.
As Accurate has said, your subjects are more average-good scaling ones rather than "low" scaling ones and so I wouldn't worry too much.
I'd definitely recommend Adv English over Standard however, if you check stats on the band breakdowns standard, almost no one gets band 6s in standard and it's much harder to get band 5s. The difficulty difference wouldn't be too much, and (at a school offering both, as many private/selective schools don't offer standard) your class will have more engaged students and teachers. Even if it was much harder or dificult, i think it's be worthwhile due to the synergy with the writing you'll have to be doing in your humanities subjects.