Realistic Crowd Stadium

Hi, i have stadium that has 80.000 seat and i need to fill these with various fan models.
Fans has animation. i cant get desired FPS even 2.000 fans. I cant use instanced static mesh
or HLOD beacuse they dont support animation.
Is there any way to manage this much animated mesh?
How AAA Football games are doing this stadium filling issue?

2D billboard won’t solve your problem ?