Romans were notoriously superstitious. They sought for auguries and omens. By our lights, the result should have been poverty and failure. On the contrary–they rolled.
We shouldn’t discount supernatural explanations. We don’t know that we know everything there is to know about the supernatural world. But even in what we do know, there are devils and angels. There is no particular reason to think that God or his messengers couldn’t answer sincere petitions for guidance in the form of omens or superstitions. The Old Testament is full of them. It may be something in the mindset of the time.
There are also secular reasons for it. It’s well known that the rational thing to do in a game of chicken is to flinch. So the winning strategy–the even more rational strategy–is to act so irrationally that your opponent is convinced that you will not flinch. The easiest way to do that is to actually be irrational. “Throw your steering wheel out the door.”
Games are something like simulations of warfare. So are politics and business. Is it a coincidence that politics, business, and warfare were what the superstitious Romans were good at?
In competition, predictability is bad. If the only way to know for sure when and by what route a legion will march is to know for sure what particular birds will be flying in what directions–or how the entrails of a ram will be shaped–the no one knows for sure.
Is God unpredictable to us merely because His mind is higher than ours, or is it partly deliberate?
Perhaps our natural man believes it is in a competition with Him.