How do I perform a migration with two different types of licenses?
You can't perform a migration with two different types of licenses. You can only launch as many migrations as you have licenses for a specific type. You can see this if you go to your License Summary in MigrationWiz.
Example: You have 12 Mailbox Migration licenses and 12 Office 365 Accelerate Promo-Mailbox Migration licenses.
To start your migration, select 12 mailboxes and use the "Mailbox Migration" licenses to start your migration. Then go back and select the 12 "Office 365 Accelerate Promo-Mailbox Migration" licenses and submit them.