Counting Boxes

One day, we need to start counting things. The problem is the boxes are all the same. No marking, no nothing. There are Box A and Box B but there was no marking except to open each boxes and see before counting since both boxes looked exactly the same. What sort of design is that! It is like lucky draw. Stupid. If everything is like that, wouldn't it be the worst nightmare for people who do inventory? Is like we don't have enough on our plate? hm... anyway, I still don't get the idea of the inventory counting thing. Isn't it a bit pointless. Example, I counted the number of cigarettes. After handover shift, the person who took over don't count again but took from it. How did they know how much is originally there or if this person did not intentionally change or accidentally miscounted? What is the idea behind? or logic behind? Example person A write 5, the next person write 5 after selling 1. The next next person write 4 after selling another one. Meaning, 1 go missing? but in fact, it wasn't missing? In actual there is 3. Or in actual sold 1, but there is 4 or 3. If a person minus, forgot to scan. hmmm...... argh....