as above, place workbench's encased further around near where your fences are, and fires behind the walls should stop spawning if the wall isnt fully around some swim around aswell, also spikey boys outter wall stops some, fire torch's aswell they hate fire some of them, if you build next to a spawner location try killing the spawner.
As for Draug spawning well that is a Raid means you have killed a boss when you kill the next it spawns lil dragons and next one if different etc.