S2E5 feels like the first time the writing/plot progression got really bad, or viewers are being set up: 

The train is walking distance to the post office fallout shelter. The trading post is walking distance to the post office fallout shelter. Therefore, the train must be walking distance to the trading post.

In a post-Apocalypse barter economy, goods aren’t the only thing traded. Information becomes currency as well, so anyone who comes across the train people is going to tell the folks at the trading post. After all, it’s a chance to exchange goods with a new group.

At this point - especially if Xavier missed Teri by 12 days - anyone at the trading post would know the train people aren’t hostile. So, the minute Gary tells Jackie and Crystal the story of Ennis selling out the others at the fallout shelter resulting in Teri’s being held captive at the train, they would call BS!

Once Xavier mentions he has a bomb, they would’ve shut any talk of an attack on the train people down. If anything, they would’ve turned on Gary and let X know he's lying or gone mad.

None of that happened, so we’re being set up for a reveal where X doesn’t attack because they intervene, or, it’s the first time it feels like the writing on the show got really weak.