I had this idea and I’m just not sure if someone did it before so tell me.
Group playbook. The group playbooks would gain levels with the characters and let them execute group moves. Let’s say your group is composed of characters with all military training and you choose the group playbook: Military squad. Military squad would give you access to (let’s say) Back to back.
When the group is surrounded and position itself in a back to back formation, you hold 3 as in the Defend move and stand in the defense of the group. The group acts as a single individual and everyone in the group can spend hold, 1 for 1, on the Defend options.
Just thinking out loud. Different group playbooks could be made like: Inquisition unit, Tomb raiders, Goblin hunters etc. Each of them would have unique set of moves and, why not, multiclass moves so you can spice things up.
If people like the idea and it wasn’t done before I would actually work on this on publish it for free.