Well, here's a script that shows objects that can't be removed with a bomb.
I understand that you can remove an army through "Battle." But how about the rest?
It's really some kind of mystery.
While trying to figure it out with scripts, I found another bug :D
I tried it on two editors and in two versions of the game - Equilibris and Vortex. So far, without success.
I remember there was a map where random events occurred every time the game started, and it included the removal of resource mines and various artifacts. I'll try to find it in my spare time.
I'm personally very interested in this situation.