On the Harpys' behaviour, is it really intended that a separate monster attack is generated for each harpy in the flock? That is what the revised wording seems to say since each only ises one Harpy's action despite being performed by several. This means that the more harpies there are the more each individual harpy can do in a single round. Given they are only supposed to attack in numbers this seems like it would be quickly overwhelming. Has anyone played out an encounter this way, and if so how did it go?
The way i read it is that each attack, narratively the harpies performs each attack as a team, but mechanically it is still one monster attack per turn. It's more they gain 1 ferocity per harpy in the group.
Let's say there are three harpies and three players. A harpy get's to go first, then the players, then the two remaining harpies. The harpy performs the Coordinated attack, in which "The harpies flock together and attack the player character who wears the most metal". Once that attack is perofrmed, it's the players turn.
So it's not that harpies get's to do more attacks per turn based on their numbers.