How can I see which (system) apps are installed with which account?
System apps come with OS before even adding accounts. They have nothing to do with which account you use.
Google accounts matter only for user installed apps either if it is a paid app or if auto backup is enabled for that app and you backup your apps.
Only exception I can think of is that your device is rooted and you installed an app that can be made into a system app, and you are now assuming that this system app is associated with Google account.