I agree-- the Scroll seems to be a recordation of the thoughts and experiences of the High Ones.
I think the irony is deliberate. The story is showing that for all their evolutionary superiority, the High Ones were still capable of error. Though their children pray to them, they are not gods and were never intended to be seen as such.
Ultimately, they brought their own demise on themselves, by not seeing or choosing not to see how far the trolls had advanced, and that the trolls were ready for self-government.
In fact, it occurs to me that Cutter, understanding slavery from his own experiences, was responding in that knowledge when he refused to look at Picknose's people as enemies any longer.