Great job with this faction! I'm always a big fan of factions that force you to choose between two competing goals. Here, it's board presence vs. scoring. It seems like you might not want to score too much at the beginning of the game (and build up your shroomling presence), but you could easily score big points on a single turn if you can get things to line up!
I am a little confused on how this faction would best move around the board? It seems the best way to "move" most of your warriors (i.e. shroomlings) to new clearings is to set up Shepherds there on previous turns and "Herd" the shroomlings to the new location. But since shroomlings only move in Birdsong, the most warriors I could ever see in a new clearing is 2 (Enlighten, Enlighten, move), which wouldn't be hard for a militant faction to pick off. If that happens, does the ball of shroomlings just continue building in the same place it was before, without gaining new ground?