Hi @calvin2,
It is hard to answer your question without some more details. A couple of points of clarification:
how many Auth0 tenants do you have? Why do you have a multi-tenant architecture?
Are you suggesting using client credentials to allow 3 party apps to access end user data? That is not good, as an evil 3rd party (think disgruntled employee) could then access data for end users that did not give consent.
Without understanding the tenant architecture, I can’t answer your main question about applications.
John