Sorry Sky, I do dynamics in Poser, and I've done multiple pieces on the same figure, but not multiple figures.
I don't know that it can be done all at once. IOW, when I do 2 pieces of clothing that interact with each other, I sim the clothing closest to the figure first, and then the outer garment, so not sure how you would sim even a 1-piece clothing item on multiple figures, especially if they're near each other in the scene.
Then again, you could just do one piece at a time, and yes it will take time, but I can't think how else to do it and not have clothing collisions.