100 locations? Are you a franchise or a large brand? When I see this type of question the first thing that comes to mind is to be very mindful of the guidelines. Not saying you are doing this, but you cannot use employee homes for listings or virtual offices.
Ok, so assumptions aside.
If you are truly in the guidelines legally and location wise then BrandA” vs. “BrandA” - Brooklyn Office is the way to go, adding a city descriptor is against the guideline unless that is how you represent your business in the real world.
You can use labels to differentiate them in the dashboard.
But really, read the guidelines closely, you could end up ina very bad place, Guidelines for representing your business on Google
Hope that helps