If you have trouble grasping the most basic of concepts as I observe, I would suggest you NOT to opt Economics. Although you have a sufficient background, but from what you're saying it seems as if Economics and you don't get along too well

However, let me be very clear that Economics is ANYTIME better scoring than is Indo-Pak. In the former you only have to derive and explain concepts as they are and you will be marked for it. The latter on the contrary is completely opinion based with too much details to be memorized -- Need I remind you, that difference of opinion may occur with that of the examiner.

Work with a Cost-Benefit analysis. See how much of both you can cover in the available time frame and what you're comfortable with. And go for it.