Big Mountain Folk fan here.
The Jadeborn were made by Autochthon from the spirits of Raksha that were trapped in stone was Creation was born. They take after him, being excellent craftsmen with a magitech theme. Back in the First Age the Exalted forced Autochthon to lay something called the Great Geas upon them, which bound them underground so that they could never threaten the dominion of the Exalted. As a (possibly accidental) side effect, it damaged their souls. Now they come in three types, Workers, Warriors, and Artisans. Most Workers and Warriors are unenlightened, which makes them weaker and dumber and less magical.
Their subterranean civilization is advanced, but deeply unfree, and under constant threat from the Darkbrood. Who are, like them, underground remnants of races that were once mighty. There's a war on, and no reason to expect it will ever end.
Under the terms of the Great Geas they can only be above ground if they're under Exalted command. The Realm has a treaty with them that, among other things, gives the empire command over a thousand Jadeborn soldiers. It would make perfect sense to throw some technicians and/or guards for the Realm Defense Grid in there, and said technicians/guards might well respond violently to apparently-unauthorized Terrestrials "intruding" on the manse. They could literally be the statues you had in mind, or else have built them.
(That's all from 2e, to be clear.)
Honestly, you could keep the crystalline automatons and still have Jadeborn be involved. While this might be fanon, there's an issue of iterative decay with how the Men of Jade create more of themselves: each 'generation' tends to be lesser than the last, and in my own brainstorming about the Mountain Folk I've often imagined Jadeborn who get desperate for alternatives to their conventional reproduction.
Yes,
that's fanon. Part of
EarthScorpion's homebrew. Nothing wrong with homebrew, though.