I believe that selling stuff in mixed cases doesn't work.
They have no records of which flavours/types/whatever is sold and get loads of one type etc left. As noticed when buying two different things from the same mixed case, the same description came up on scanning both of them.
In Lidl, I buy their stir in pasta sauce - only the sundried tomato and the peppers one. Yet I went through 8 or 9 cases and every single pot was tomato and bacon - bar one sundried tomato which I took. The problem is that the pasta sauce will be like this forever as get a case of 15-20 pots and customers will buy the other two flavours. Adding a further 5-7 pots to the tomato and bacon pile per case.
Then there is a health n safety issue. The bottles of pop and squash come on boards and customers tend to buy one or two of the varieties more than the others. This can make the boards unstable and could easy topple over onto a person. 2l bottles weigh over 2kg.
I know its a cost thing but putting out three smaller cases in the same space doesn't take that much longer.