Vellum paper animation - pin to target issue

[OllyFJ]

I'm trying to create a 'swarm' of paper following a path, I'm using vellum to simulate it with pin to target constraints, however when I lower the constraint stiffness to get more organic movement, the animation starts to bounce, can anyone advise me on why this is happening? I have no other forces acting on the geo

This is the guide animation I'm using as a target - 

And this is the bouncy sim - 

Scene file too - 

paper_swarm_demo_01.hip

 

Thanks

Olly