[@Muttonhawk]

For clarity, my question mainly concerns the Hain that would be in that area near the Venomweald and Firewind that Ommok is invading. Because I didn't explicitly mention what "large swathes" of land Ommok took, I'm going to scale back the size of his conquests significantly.

Thinking about canonizing some tribal confederation that would offer a little bit more resistance to the ogres. 

So given what you just said, I'll go with Slough worship and some Stone Chippers being present. Probably will take the liberty of saying that the "shrines" to Slough are just sacred groves or trees, maybe like the Irminsuls from Germanic pagan traditions.