I will point out something I thought was obvious, but from a IRC conversation it would seem that is not the case.
When dealing with time critical food shipments, then yes multiple caravans can be advantageous. If we need 1000 bushels to arrive to prevent starvations, then multiple caravans (almost) ensure that SOME food will arrive so at worst you reduce the effect of starvation if the amount you can ship only just covers the amount needed.
