There's a wreck in Hudson of a Xeno shot down by a Unioner but not much more detail. I've read all the rumors at Barrow but none of them talk about Unioners. My Xeno's bio incorporates the wreck as that of his father, so I know one Xeno who'll never trust Unioners...
The two groups have very similar stories, making me wonder why Xenos are considered terrorists when Unioners are not. But the similarity of their stories doesn't mean they'd make good allies. Yes they have common enemies but at the same time they are both powerfully proud of their own Houses. Neither faction would risk empowering a competing House with an alliance like that.
Xenos and Unioners biggest beef with each other is most likely turf. They set right next to each other and piss across the fence every once in a while.
Quote: The two groups have very similar stories, making me wonder why Xenos are considered terrorists when Unioners are not.
If you read the info card, it says that the Unioner's agenda switched from terrorism to piracy. So initially they were, but their goals and obstacles changes I suppose.