We all know DRIVERS in Blender is our key to connect live data between objects. I would like to also point out Animation Nodes in handling such matter using nodes more visually and a lot easier.

With FACE ANIMATION and all the shapekeys data, it becomes quite interesting when character have different number of shapekeys and naming system. So logically we need to find a method to make connecting the shapekeys simpler.

I wish everything can be automated, but for now semi-automated is good. Maybe in the future we can use machine learning to match face expressions?

Enjoy!