Looking at the human population of Dragon Pass as a whole, these are their largest cults:
Earth Religion – this is one of the two largest cult groupings in Dragon Pass with about 134k initiates, with Ernalda having 117k initiates, and the rest of her household having another 17k initiates.
Orlanth and the Lightbringers – tied with the Earth religion with 134k initiates in Dragon Pass, with Orlanth having 87k initiates, the other Lightbringers a total of 30k, Humakt with 13k, and Storm Bull adding another 4k.
The Lunar Way is in third place, with 82k initiates, the vast majority being in the Maize Belt of Tarsh. The Seven Mothers has 66k, and other Lunar cults (mainly Hon-eel) adding another 26k initiates.
The Solar Religion is a distant fourth place, with 25k. About 20k initiates follow Yelmalio, and 5k follow Yelm.
If we count the Darkness religion of the trolls, that gets us another 52k or so, with Kyger Litor along being around 22k, Xiola Umbar being 13k, Argan Argar a little over 10k, and Zorak Zoran being some 4k.
Xiola Umbar being 13k ! There are a lot of trollkin. And their very existence is somewhat disparaged by the common trolls.