Let's see;
-The Moonsong and crew (Moonsong, Theon, Asha, etc)
-The Queen Rhaella and crew (Diana, Lothos, various Leshy, Little Valyrians, etc)
-Mercy
-Three Erinyes
-Two Verdant Wolves
-Two squads of six Minotaur Fighters
-Two sets of Elemental Wyrmlings (We have five sets now)
-Three dozen Lesser False Ravens for comprehensive scouting (We have several hundred now)
-Six Greater False Ravens for scouting, spying, and coordinating Lesser Ravens
-One 5th level Wizard, one 4th level Wizard, one 5th level Archivist, one 4th level Archivist.
-Breath Taker or Blight's Bane, and a contingent of Groton warriors. Maybe some traders, too?
This represents a good amount of firepower and spread of abilities. Lots of people who could gain experience along the way, too. Both ships, but especially the Queen Rhaella, have a huge crew capacity, so lots of mundane sailors can be included as well. If we send them off with a bunch of Raise from the Deep scrolls, they could salvage and crew ships along the way.
With the Tritons along, and Diana's ability to easily grant others underwater survival and movement abilities, they could also seek to establish diplomatic contact with other Triton settlements as they travel.
I really like the idea of this trip. It could last for several months. Lots of good interlude fodder, too!