The written record about Shona religion was produced by missionaries, settlers and a colonial administration, and it was produced in a territory whose land was being taken.
That context is not background. The mhondoro mediums were directly involved in the risings of the 1890s against colonial occupation, and again in the liberation war of the 1960s and 1970s, and much of the colonial documentation about them was gathered as intelligence about an opposition. It is detailed, and it is the record of an adversary.
Missionary accounts supply another layer, produced by people intending to replace what they described, and a persistent feature of that literature is the argument over whether Mwari could be identified with the Christian God, which shaped how the tradition was reported in ways that are still being unpicked.
The most valuable modern scholarship has come from historians and anthropologists working from the 1960s onward, including Zimbabwean scholars, and it has generally been careful to trace how the tradition itself changed under a century of pressure rather than presenting a timeless system.
The tradition transmits through mediums, through the training of those who serve at shrines, and within families. It is not a body of doctrine.
The atlas describes the order of the tradition and reproduces nothing held by the shrine keepers or the mediums.