What are some tips on making an advanced RagDoll?

After watching the " Bullet Train " video, I am convinced my rag-doll could be better. At the moment my characters fly and roll around the map like glitches from the depths of H E double hockey sticks.

Spend some time setting up your characters “physics asset”

Looking more for setting tips. Should I be using boxes, cylinders, spheres ? Is more better ? Should all joints be spheres ? Are there any particular settings that are a must do for rag dolls to work efficiently in game ? It seems that the " Simulated " version of rag doll differs a lot from the actual games rag-doll. Is this because of gravity, bone mass ? I have looked for tutorials and none really seem to go in depth on this subject.