I have arranged villagers into homes which they are not able to get out of, however this is the second time that my weaponsmith has disappeared without being killed. The latest villager was named too which I thought would reduce the likelihood of it despawning. This villagers property follows the same basic design as the others where he has a few blocks to path find between a bed and a work station, with a door in front of the workstation to allow the player to access the villager and to stop enemy mobs from getting close to the villager. The surrounding area is completely walled off too and I have not found them wandering around nearby.