And over time what would the amount lost under both cases tend towards? If this is seriously what people are doing I would suggest we need to start charging each separate caravan sent. But you are making the mistake here of biasing the results. You could send out the ten caravans and lose anything UP to 10, the same goes for the 20 caravans. Only over a VERY large sample are the results going to result in a true 10% loss of total caravans sent.
End result, no matter HOW many caravans you send, the chances gods could end up making you pay for it. It is only OBSERVER bias that makes people think that sending the extra caravans building in protection. Thus my comment is correct. People may decide to send more caravans because they think that is a safer option, but we don't need to modify game mechanics to prevent this, because it is not a true advantage.
There is a (1 gold) cost to sending each additional caravan.
And there's the added benefit of maybe not hitting a wall on the other end--spreading out your caravans means that they have a chance to eat the food or send it further on or at the very least set up more buy offers.
