Question Make Character Rig Follow Other Character?

Hey!
Basically, I'm working on a VR project where the player can jump into any character in the scene and control them. I will use either FinalIK or the AnimationRigging package for the player's body presence, but my question is, how can I then make a selected rigged character instantly follow the position and rotation of the player's body?

I don't think I need an animator controller for this, I simply want each of the selected characters' bones to follow the position and rotation of the player's IK body. In other words, how can I get one rigged (non-animated) character to match the pose of another animated character?
Hopefully this makes sense...

Any ideas?
Thanks!