Vanch, Imther, Aggar, Holay, and Tarsh are a collection of Theyalan lands ruled by client kings supported by (and responsible to) the Red Emperor. For the last few generations, that was handled by Appius Luxius, the Provincial Overseer in Mirin’s Cross.
Looking at the Provinces as a whole, the big three cults are Ernalda, Seven Mothers, and Orlanth, with Yelmalio leading the next tier. About 100k people worship their grain goddesses directly, as either Pelora/Oria or as Hon-eel the Maize Goddess.
Ernalda 167k
Seven Mothers 165k
Orlanth 132k
Yelmalio 72k
Pelora/Oria 52k
Hon-eel 51k
Lodril 41k
Hwarin Dalthippa 40k
Humakt 21k
Issaries 20k
Oslira 18k
Chalana Arroy 18k
Lhankor Mhy 13k
Yelm 10k
Jajagappa 10k
Other cults 87k
Some of these cults are going to be very localized. Jajagappa’s cult is almost entirely in Holay, as is Lodril’s cult. There is a surprisingly large Storm Bull cult (some 7500 initiates) in Aggar, but is otherwise absent.
Aggar is very much a strange place. Basically you have a small area of Lunar colonies, which extracts tribute from a much larger Orlanthi area.
The main cults in Aggar are:
Orlanth 36k
Ernalda 29k
Seven Mothers 14k
Other Lightbringers (Chalana Arroy, Eurmal, Issaries, Lhankhor Mhy) 13k
Pelora/Oria 10k
Storm Bull 7k
Yelmalio 7k
Hon-eel 7k
Hwarin Dalthippa 7k
And then you have that strange City of 10,000 Magicians. A strange EWF legacy.