Have you checked out the instance tool?
It lets you easily switch between instance and mesh and its cheap - like $10.
Other things to keep in mind:
You can easily simulate rigid bodies in the scene, then choose “Keep Simulation Changes”.
So workflow would be:
Layout 100 meshes with simulate physics.
Simulate, “Keep Simulation Changes”.
Turn off Simulate Physics.
Use Instance tool to convert to instance.
Rinse and repeat…
**This assumes you want to use physics to position meshes at design time, not simulate at runtime.
If you want to simulate at runtime, instancing is not what you want.