Story Teller Help?

[Wolf619]

I've been trying to set up a story teller to do bigger raids right from the start but I always seem to end up with just one raider for the first few raids.
How do I go about making the raids bigger right off the hop?
I noticed the Call of Cthulhu mod does big raids when they raid, but I can't figure it out.
Any help would be appreciated thank you in advance!