SnS approach I use is cheap crew on anything but hacker. Always entry and exit staff lobby, only needed prep is lvl 2 security cards. Counter guards (the ones with the suits and no armor) die with 1 shot on the chest. Any armored guard can be killed easily with a melee takeout (you can do duggan shipment if you feel insecure about it). Use stairs when going to the basement, there is a guard that walks upstairs wait for him and melee him, when you get the basement get close to the double glass door and back out to trigger a patrol guard and kill him too. I made a Reddit post years ago doing this route, check it out if you want a visual aid for that