Clarifications on the harpy

[Seven]

When a monster has a human head, I tend to give it human intelligence.
Generally, a harpy with arms is often pictured with a club.
So, I'm thinking about the lower range of human intelligence.

I was thinking the opposite with respect to nets.
A net seems less dangerous than the harpy's song.
But could a harpy without arms weave nets? Probably not.

However, there is also the matter of scream tactics--a group of harpies being called a scream of harpies. If a scream of harpies is singing, I'm still going to allow a single saving throw to avoid the effect, not one per harpy. Then the question becomes can a harpy mesmerise more than one victim at a time? If so, there is no point for more than one harpy to be singing and the others are free to use more complex attacks. If not, each harpy will focus on the first individual to fail a save to it. Then harpies with no mesmerized victim would be free to perform complex attacks.

Also, a hunting scream of harpies would probably be satisfied with 1 humanoid victim.
To quote Tom Cruise, "That's a big meal.".
I assume 2 harpies could carry a mesmerized victim, maybe 4 if there is an heavy armor involved, each grabbing a limb.