Hear me out, but my suggestion is to NOT decide to do a different module *right now*.
If you do, the whole time you're studying for business maths, the moment you don't understand something, you'll simply tell yourself, "nah, it's fine, I won't do it on the exam". This will instantly cause your SAC rank to suffer - even if you do manage to maintain your rank, you might've been able to do even better and attained a higher rank had you not spent the time leading up to it as if it would go on your exam.
After you've done all of this, when you're actually approaching exams, then, and only then, decide if another module might suit you better. Also, and I can't stress this enough, if you decide to do another module, actually study for it. Yes, you do methods and specialist, you know a lot about linear relationships - but there's a lot of different styles of questions that will be on your exam that you will have never seen before. This includes things such as the "feasability region", which appeared on the exam last year and would've confused all the methods kids who decided to do that section on a whim. (there's always at least one, generally quite a few...)