I think as modelling accurate articulated body dynamics is feasible but when you add deformation (muscles) it gets much harder.
Would be similar to the typical simulations of humanoids. If you need to model the deformations of the human body, or get a proper model of tendons that make up humans, it'll be more difficult, but possible.
Proper simulators for those exist, you essentially need an engine with a compliant contact model. MuJoCo is the goto here, see:
https://mujoco.readthedocs.io/en/stable/modeling.html#muscle... https://mujoco.readthedocs.io/en/stable/computation/fluid.ht...
These explicitly model biological muscles. IIRC it was originally created to model human hands (I could be misremembering though).
Really depends on the fidelity you want.
Edit: I also work in rigid body simulation for robotics.
Indeed, it entirely depends on which axis you want to focus on. A loose trade-off chart would be speed, stability and accuracy. You can only have two of these in a simulator.
Robotics folks probably want speed and accuracy. I'm from the video game industry so I generally look for speed and stability.
Note: This is a loose analogy and recent techniques are already blurring the lines between these axis.
I’ve often thought it would be very handy to have a proper simulator for being able to simulate and identify inefficiencies in one’s technique, but no idea whether it would be feasible to do.