There are ways to make things very difficult to break into and steal. you mentioned the puck locks. those are around 40 bucks at Lowes that come with very heavy weldable plates for trailers or carriage bolts to through bolt boxvans or enclosed trailer doors. to keep folks from stealing your car or truck, for around 200 bucks one could buy "boots" that police and universities use for vehicles that do not pay their parking tickets. the "fuggetaboutit" bike lock from kryponite cannot be cut even with 48" bolt cutters. you could secure small equipment in open trailers with these if folks wanted to jump the sides and grab and go.
on our front gate to our shop we use a kryponite lock with 3/4" ship anchor chain I got on ebay. sure, it could be cut by someone with an angle grinder or acetylene torch. but those make sparks and take time.
The problem is employees. They know when you are gone, they know where the keys are and can make copies easily. The only thing that saves you there is cameras and offsite video feed. but they usually know where the cameras are.