The more I dug into this faction the more my questions were answered. It really reveals a lot about how you've planned each step through! I was wondering why you would build, but it does feed directly into the way they gain VP! It's also really thematic especially with regards to swarming which I find really fitting.
Just from personal experience when I worked on my Crocs faction (they also used to score by having other warriors around), it sometimes is difficult to balance a faction that scores off of an abundance of other warriors (and their removal from feast). Just since there's so much variance in warrior count on some games, and it kinda de-incentivizes getting involved in conflict with your own warriors.
That's def not a knock against your faction, and now something that can be monitored for through playtesting... Which you absolutely should keep working on these fellas cause there's a lot that works here!
Great stuff :)