My customer has a SharePoint 2013 farm running in Azure through a VPN connection extending their Head Office on premises AD.
They also run Dir Sync at the moment for the head office users to make use of exchange online through Office 365.
They have 70 plus schools around the world each with their own Office 365 tenancy, so with on prem but most only in the cloud.
Can I use the AAD Sync tool to replicate all the individual tenancy users in to one global Azure AD?
SSO is not required.