Issue:
PlayerData is currently not really usable if you want to have multiple Prefabs of something using it, as we currently don't have an unique ID we could reference that also doesn't change.
Currently you would have to implement your own system giving out IDs to your scripts, so that you can differentiate them.
Suggestion:
A
relatively
easy way to solve this is by giving us access to NetworkIDs on runtime.
Doing so would allow us to differentiate between Game Objects when storing PlayerData, by adding that ID to the key.