How do I get more raiders at my Nuka-World raider outposts?
It's similar to building a normal settlement. First of all, you have to keep them happy. Places to sleep, drugs and the transmitter are a must-have if you want your outpost to grow. Additionally, you have to assign "slaveposts" (I just named them like that) to your outpost in order to supply the outpost with food. Do NOT make your raiders work. You can do that, but that won't make your village grow. You have to make life as easy as possible for them, and you can only do that by conquering outposts around.