It's pretty late to be doing it, but you could just distribute it outside for birds to pilfer for their nests.
That is true, although even with better security it ends up being a known quantity. Shifts are relatively static because whoever's in charge of security is lazy (which I'm sure you have experience with), and a building stays where it is.
There is a fulfillment center for a telecom down in Seattle that has three guards, and the shift hours haven't changed for as long as I've known someone working there (~2 years). One guy in the security room, one on the inside, and then one in the shipping bay.
And I used to know someone who worked in the security business before transitioning to insurance, and they had experience with 5 different job sites. Same deal: no change in shifts, same routes and routines.
Not to say it's easy, of course. If it were, I imagine it'd happen a whole lot more. But I guess my point is that if you're capable of hijacking shipments on an open road, you're probably just as capable, or more capable, of tackling a warehouse.