[mothered]

In terms of reasons for DNA it makes complete sense it could all be gone if it arrived at the same time which I would expect to happen

Exactly right.

If (for example) someone walked by and was Intending to steal the goods, logic has It they'd take both packages. Why leave one behind?

so far on my checkout it says the same date for all items.

Looking good so far.

Let's hope they arrive together, and not during different times of the day.