Military schooling and subjects

[Faustie]

Stop considering what grades you need for infantry, and start considering what grades you'll want on your CV at the end of your military career. You won't be an infantryman forever, and once that ends you're going to want decent grades. Via military, I'd really recommend taking subjects suchs as maths, chemistry, physicst - You said you were interested in being an engineer, well, military experience + those grades would make a very nice combination. You won't get to the highest paid branches of engineering i.e. nuclear/chemical unless you do further schooling after military, but you'll have a good basis for civil, mechanical, possibly electrical engineering depending on what you do.