In this cinematic, I did all the simulations on Ethan's hair, dog tags, and holsters.
Using the same method that I did on the coat, which was:

"About the dynamic simulations, there are 8 joint chains in the coat, and each chain has between 6-8 joints. The chain then has spline IK applied to it and the spline is made into a dynamic curve, which can then be altered to behave the way you want. Like, giving it more weight, or more drag, etc. Also, you can set up collision objects with the curve so it doesn't penetrate geometry you dont want it penetrating."

..except that the hair only uses 4 bones total, and the tags use 4 as well. holsters use 6. so for very little extra bones, the result is very nice and takes no animation time. It's all in the initial setup phase, and after that it takes no time to apply dynamics to any animation and get it in game, because the result can be baked back down to the joints.