The next step was to figure out what the text logs have to say about this because I thought I had covered off all the culprits listed above. When I checked the migmctl.log on the site server I was performing the migration to I noticed there was something SQL related I wasn't expecting.
[MigrationManager]: Set the schedule item 16777217 to Failed.
ERROR: [MigrationManager]: Error occurred when trying to make sql connection to server.domain.com. Contact product support for help. Error Information -2146232060, Login failed. The login is from an untrusted domain and cannot be used with Windows authentication.
I didn't really troubleshoot why the authentication was not happening in depth because the account to be used for the SQL connection was in the same domain as the SQL server. As I result I opted to create a local account on the source server and give it SA rights to SQL. This in turn resolved the issue and I could continue on to making migration jobs.