Firstly, I doubt you are that interested in material engineering, otherwise you wouldn't be thinking of a SIM business course as an alternative.

Secondly, are you good in math? If not, you will suffer in engineering regardless of whether you are interested in materials engineering or not. You will become a mediocre engineer.

Thirdly, what's so interesting about material engineering? My friend did material engineering in NTU and he is now working in a factory in Tuas with lousy pay and prospects, working alongside 95% FTs who can't wait to kick him out so that they can bring in their own countrymen. That's a lousy way to earn a living.