Well the procedural mesh can be generated with a tool script, so you don't have to do it manually in a DCC app. This is how voronoi works, very few games (if any) actually generate this dynamically as it's probably too slow while playing the game. So in whatever case, you will be working with pre-made meshes (it's just a matter if you have to do it or the computer does it for you).
If you want to go the easy way, I would recommend modeling stumps (like for the elbow, with a bloody texture or bone sticking out). If you just scale the skeleton, you will have extreme stretching and shrinking on the texture UV and it won't look realistic. But you can create the stumps by hand (for example, the elbow, the neck, ankle, etc.) and have them be high quality. Then when a body part is shot off, you display the stump as a bone attachment (this works in Godot, no special code needed) and spawn a RigidBody at the same transform and give it some velocity (according to the bullet direction). This honestly should look okay.
