Ok, so I noticed I'd neglected to destroy a Type I government of Baktria's when I took their city to the North of Baktra. But, what I also noticed is that as a result I had access to stone walls and a few other things, that I wouldn't be able to tech up to normally.
This also means even in places you can get the reforms, if you don't destroy the enemy government straight away, you can do things like build large roads and stone walls.
Is this meant to happen, or is this some sort of oversight/bug? It doesn't feel "wrong" at all, as I don't see how you could forget how stone works once you make your way a certain distance North, and I suppose it could be used to represent rounding up their government officials and saying "Look, we're your boss now. So build us a damned wall!" or something, in a similar manner to Ghenghis Khan.
Thoughts on this?