Script to group mailbox delegates for O365 migrations

As part of our preparation to migrate from Exchange 2007 to Office 365, we need to identify groups of mailboxes that will be migrated together which are delegates of others.  Dumping a full list of who the delegates are for each mailbox in the environment is simple (Get-Mailbox -ResultSize unlimited | Get-MailboxCalendarsettings | where {$_.resourcedelegates -notlike ""} | fl identity,resourcedelegates), however it's the logical grouping of mailboxes based on who the delegates are which is the challenging part.

Does anyone have a script or logic to accomplish something like this or has gone through this process previously with any tips?

Thanks