There are about a 1.5 million people or so who are initiated to the Invisible God and follow the Rokari rites. Of those maybe 3% are the “priestly caste”, called zzaburi. That comes out to about 45,000 people who are trained as sorcerers, which is an immense number if you think about it.
Rokarism places strict restrictions on the “priestly caste” and emphasizes the material prerogatives of the “ruling caste”, although many believe that under Rokarism the zzaburi hold out the highest ritual status for themselves, second only to ruling members of the Rindland dynasty.
Of course only a very few of these sorcerers are at the beck and call of the rulers of Seshnela. Most support themselves by performing rituals and ceremonies for their local communities, and spend their time studying or engaging in magical activities. They are full-time professional magic-workers.
However, many nobles have granted lands or workers to support the local zzaburi, and some zzaburi study magic for its own sake. Some of these have resulted in great complexes like Buddhist monasteries like Taxila, Nalanda, or Enryaku-ji.
The greatest of these is Leplain, a vast complex of temples and “universities”, often called the Blue Temple. There might be as many as 3000(!) sorcerers training and studying in the Blue Temple! This is the center of Rokarism, and I suspect most young recruits to the zzaburi caste are sent here to learn and train.
Ideally, the zzaburi would prefer if the rest of the population relied completely on them with regards to magic use, but of course that is not going to happen. There are numerous spirit cults, deified ancestors, revered heroes, abstract entities, and so on.
So when we thinking about Rokarism, it is worth keeping in mind that it was a reaction against the widespread destruction caused by the God Learners. Malkioni philosophers reached back for a primary source – the original teachings of Malkion, cleansed and redacted by Rokar. And so the Rokari look to the Brithini as analogues (but believe the Brithini are in error rejecting the later revelations of Malkion, such as Solace).
Many Rokari prefer an abstract and philosophical concept of the Invisible God, and imagine the Runes as abstract archetypes, like the Major Arcana, personified as gods (e.g., Worlath, Ehilm, Humct, Gata, Seshna Likita, etc.). These gods are not given cult by the Rokari, and the personifications are usually considered wayward.
But beneath this Rokari philosophical abstraction is a churning sea of folk religion. Ancestor worship, spirit cults, old tribal cults, local deities, more abstract deities of phenomena and behaviour, etc.
That’s a dangerous place! How many of those sorcerers inevitably start meddling in the Invisible God’s domain? Think of it as a vast featureless antechambers. We can stay here and meditate and gain Solace or Even Joy. Or we can devolve and travel along the Runic paths. But the further we go, the more our philosophical perfection devolved into a mire of existence and contradiction. Energies take on personalities, split, combine, and are manipulated by others.