I did standard english and did decent so yes it's possible to do well, but not particularly easy since you are marked alongside the advanced cohort (common module). EALD is completely seperate so you aren't competing with the advanced english students for high marks. If you are competent at standard english you might smash EALD.
Anyway, succeeding in standard is not about your ability to speak/write English - it is more about your understanding of the texts and how they link to your modules. If you aren't super confident with the books, it might be a good idea to listen/read the texts in your native language to really get a good understanding of the themes and ideas. You can then use these concepts in your head to write more meaningful essays that will be rewarded with better marks.