Looks like they mostly have things organized by size for shelf space. The more shelves they can fit in there the more stuff they can get on them.

The larger tea boxes probably force them to put it on the top or bottom. And since they probably want to keep "fluids" together and liquid items are traditionally put on the bottom (in case there's leakage so they don't have to risk a damaged product ruining other shelves as it runs down) that's where it ended up.

It does make sense to have them together though since you really do get one if you have the other. I wonder if there's a way to swing it. Moving shelf 6 up to 2 and squeezing them in there could be possible since they probably double stack with the cans nicely.