Sims not accurately programmed to train for scenarios that can and do happen in extremis.
I don’t think that’s as important as people make out. The detailed response of an airframe to “edge of the envelope” events in real life is often highly dependant on things like CG, yaw/roll/pitch angles, asymmetry, entry rate, wing loading, air density and many other factors. Every one is different, sometimes remarkably so.
What needs to be trained is:
1. High-altitude stalls are BAD, don’t go there.
2. If you do end up there, it will most likely need control deflections and pitch angles that you’ve never used/seen before to get out of it.
If the sim is up to replicating that, then it’s good enough. We are trying for a generic recovery procedure, not a specific finessed one.