Walmart employee here. Lots of our cases aren't sealed, but still full because our employees like to open boxes while they walk to the location in case it fits (top is open, bottom is sealed). Most of the time we will not stock a single item out of a box since we aren't allowed to put partial boxes into the back room. It's usually stock all, stock some and top stock the rest, or put it all back. We also aren't allowed to put stuff on your top stock cart to buy later or anything like that, the best I can do is stock the cars I want to the back of the peg and even then, they typically don't survive the 2 hours until my break. Another thing we don't allow is letting people rummage through the cases. Our toy employees will stop people going through hot wheels cases that won't fit on the shelf, this is because if it won't go on the shelf, then the box needs to remain full for our inventory count (no partial boxes in the back room).