[jib]

Shuffled is also a feature. You almost never buy a 32" TV and a 34" TV at the same time, right? So it is highly unlikely that similar items would benefit from being next to each other. It helps for finding if that was a problem, but finding is solved by computers anyway, so the layout can be optimised for pathing instead.

[NeutronBoy]

If you watch the Kiva video linked above, they also optimize for popularity of items - so as items are picked out of each crate, the remaining items are analyzed. If there's no popular items remaining on the create, they go and park it at the back of the warehouse.