@safiredesignengineers
I don`t trhink it is currently possible to have multiple pieces of Stock that are not joined together but you can get a reasonable view if using Fixtures IMHO.
Here is a similar project where 4 Vises were required to do 4 operations to create a part, each WCS has a solid model of the previous WCS operations as a Solid Stock, to get it to simulate the models were joind together by a small "bar".
One of the Vise jaws was also linked in to show the cut into the Jaw as well as the collision and it does show what is going on quite well, I dropped the height of a Contour in the first Setup to show the cutting of the Jaw as an example 🙂
If was done as an exercise by two young female trainees I had at the shop from the local College, they were 18 and 19 years old with about 3 months experience of Fusion 360, done during much giggling and digs at the "old guy" trying to be serious, to be fair, they were fast, efficient learners, they are definitely the future when all us "Dinasours" are gone 🙂 🙂 🙂
Hopefully this is something that the Developers can produce as it is pretty handy, not sure if it can be done using the new Machine Simulation as I haven`t delved into that yet 🙂

Screencast link
https://autode.sk/2Udu15D