Engineers and Scientists – What They Do in XCOM 2
XCOM 2 has you in charge of soldiers out on the battlefield as well as the day to day workings of a base. As Commander, you choose what is built and researched next within the HQ, effectively improving the forces against the alien threat. Besides you and your soldiers, Engineers and Scientists are the greatest assets to your base.
Engineers are the ones that can excavate different areas of the base in order to gain supplies and other resources as well as make room for building a facility. Engineers will be able to take these empty spaces and build whatever facilities you want, as well as work within them in order to provide bonuses to said facility.
Scientists help out Dr. Tygan with researching new technologies. They are incredibly useful to make new tech roll in, in the minimum time possible. With certain, important research (sometimes necessary for the main missions), you actually need multiple scientists working at once or else you won’t be able to complete it.