Do I need to create separate tenants for file archiving and email archiving

PROBLEM:
Do I need a separate tenant for file archiving and a separate tenant for email archiving?

SOLUTION:
It is not a must to create separate tenants for email and file archiving. You can just simply create separate databases – one for file archiving and second for email archiving. The recommended database count depends on the archivable mailbox count (in case of email archiving) / archivable root count (in case of file archiving). For more information about the database-size recommendations refer to section "What is the recommended database size for email, file and SharePoint archiving."