same, I'm trying to make multiple ragdolls do the same animation, but everytime I enable the animation on one, eventually another will stop dead in its tracks

Shame nobody's answering this, since multiple npcs dancing ain't working for me too.

I figured it out, guys from a year ago, you just have to click on "add current selection" after you configure a dance to an NPC, and then do the same to the second NPC.
If this explanation doesn't make sense to you, just experiment around the "add current selection" button.

then left click on the ground.