Distorted Humor wrote:
... as the impression is that "The Tin Man" Takes place in the fronteir where the exact location of the two borders is not set.
My impression was that the events of Tin Man took place outside of both the Federation and the Empire, in open interstellar space -- unclaimed territory.
This would imply that the RNZ isn't a continuous bubble completely around the Romulans, but rather a buffer/wall in-between the Federation and Romulans. And the Romulans can move and grow in any direct they please, as long as it isn't towards the Federation.