A lot of the times the thieves get a job there and on truck day, they steal the merchandise before it ever gets scanned in.
Walmart’s computer system is such that they know their inventory from warehouse to truck to store.
The only thing they aren’t sure of is the shrinkage in the store even though they have a location where empty wrappers, boxes, etc. are to be placed when found by stockers.
Stealing items off a shrink wrapped pallet often higher than your head would be extremely difficult. There are times when a trailer arrives that’s literally packed so no excessive space is left between the items and a roller conveyor is used to unload and place on pallets
That’s the exception rather than the rule.
Once a year an outside company inventories every store.
I never saw a broken case.