> Well, sometimes building a consensus is more important than accuracy. A shaman’s random decision is better than a more optimal decision not everyone can get fully behind. This is especially true in war scenarios where conviction is key.
> Sometimes it is better to believe that a decision is sanctioned by a higher authority than to know that it rests on mere conjecture, as it usually does in the real world where we’re always dealing with incomplete information.
> And sometimes it is better to have a truly random decision than to continue to follow the predictable inclinations of one’s established prejudices. Surely, the enemy will not be able to predict a shaman’s completely random decision.
The author then makes conclusions about the beliefs people in the past had about divination.
This appears to have been derived entirely from the hunches of the author. That's best described as "making shit up."
It starts with the epiphany: "hey, maybe it is actually possible to understand the past" and then doesn't make the barest effort to consider that there are approaches for doing this.