The Stitched are just great all-around against Gremlins. Early on, with Creepy Fog, they are one-way LoS blockers. I say one-way because Diving Attack doesn't require LoS. Later turns, they take advantage of the Gremlin's horrible Wp4 by Gambling with them.
As for activation sequence, this part of my first turn is always the same regardless of my enemy. I'm sure this is not the most optimal way to do it, but it's worked for me so far.
Deployment is Young Nepihlim and Desperate Merc both base to base with the BBS and a Tot in melee range of the Merc.
1. Activate BBS, Defensive Stance, Blood Offering, cast Blood Magic (doing 3 wounds to Desperate Merc) and giving Fast to Young. BBS has 1 Blood Counter.
2. Activate Tot, kill Desperate, Healing Flip on BBS, Drain Blood, try to cast Grow. BBS now has 2 Blood Counters (gained one from Blood Sense) and 1 Corpse Counter (from being in base contact with Desperate when it died).
3. Activate Young, cast Mature (using Blood Counters on BBS), placing the Mature in front of the BBS while remaining in base contact. Depending on my enemy/terrain, I may then cast Carry twice to move up the BBS.
The rest of the activations will depend on what my enemy does.