- It's possible that Lords and Ladies maybe an inadvertent backlash against Wendy and Richard Pini's ElfQuest.
- More likely a backlash against how Mary Sue all elves have been in fantasy since Tolkien.
Herne the Hunted is a very young god, not an ancient one.
The notion that small furry animals would have enough imagination to conceive of a god, thus elevating a generic small god to be their patron, seems unlikely given how such animals' thought processes are described in other books. The rabbit from Moving Pictures
said his pre-Holy Wood vocabulary consisted of two verbs and one noun, and the general consensus (barring some probably-metaphorical conversations in Reaper Man
) seems to be that most Discworld animals divide the world into things to 1) eat, 2) run away from, 3) mate with, and 4) rocks. No head-space for a "5) pray to" category, there.
However, the witches mention in Wyrd Sisters
that the late king Verence I used to hunt people
through the forest as a means of executing criminals. Such fugitives probably gave Herne his first injection of belief, sufficient to let him manifest and influence the world for however long these hunted criminals could evade their pursuers. Once he achieved consciousness, Herne hastily spread knowledge of his existence to lots of people around Lancre, so that the prayers of poachers avoiding the gamekeepers, kids playing tag, and the widespread human belief that prey-animals deserve
such a deity to call upon would keep him around, albeit as an extremely frail micro-god, scarcely any more potent than Om-as-tortoise.
In the process of establishing himself in this way, Herne may also have absorbed traces of a much earlier prey-protector god: one who'd been worshiped in ancient times before the Dancers were erected, when Lancre was plagued by elves and all
humans feared they'd be hunted down by them. Hence, the recently-made godling Herne freaked out when that much, much older part of him sensed that "they" were coming back.