One of the shops I worked for payed the sales people very average for a cashier job, but had a security room and hallway with multiple entrances into the store and outside with at least 1 extremely well armed guard but usually more on busy days. Employees were trained to never intervene and communicate instead.
Another shop has a ton of cases and employees, and they're all paid very well. High base pay plus a commission on most items. All employees given a stipend for training and free ammo, group training, visiting security professionals. The owner acts like the employees are his family. I tried for YEARS to get a weekend job at this shop but there was never a spot for me. This shop (which is in MA btw) 100% they will shoot you, and they were only ever robbed once that I know of, outside business hours.