Based on another thread . . . what planets in the periphery are split up politically? This would be independent planets of course, but due to the way they are split up into different polities it opens up some options for raids that does not exist in when a faction has access to space.
All I can think of is . . .
Astrokaszy (before Rim Commonality took them late 3000s)
Antallos (before Raven's clean up)
Randis