I don’t think any real people would have survived the basic training portrayed. Couldnt figure out how the gas masks were so important for civilians, but not mentioned in basic training. No attacks from aliens occured during basic training except periphery. Aliens would have weighed tons, inertia would not allow them to move so fast and be able to survive at earth temperature and pressure. Them being more advanced or capable is not necessarily mean they are smarter and based on their ability to produce tech from their bodies, may be non-setient. Excellent story telling, so so character development. Poor science and research. If drill instructors treated trainees like depicted in book, it would be bad.