I want you to know that we have had a look at this and it is indeed a bit of a bug. The game originally didn't show unarmed survivors in the compounds, so it never used to be an issue.
When we added in the Bounty system, players started disarming their leader so the bounty couldn't be collected, so we put them back in. Obviously there are some holes in the AI that are causing these new issues.
The quickest / simplest solution is for us to make it so unarmed survivors are automatically given a weapon during a raid.
This patch will go up next week, along with some other minor tweaks to the AI that I think should improves things a bit. As always, I will appreciate any feedback.