Blue=Crownbreaker forces. Red=Sanctum forces. Green=Tide, Purple=Revenant. Click to show each step of the plan. The plan itself can be seen in the Notes and Credits.
With the Crownbreakers' support, we head through Merry Meadows and push into Spindlewood. We should obviously leave several people defending at Fields of Valor, and we should send a total (including our allies) of 6-8 people, 2 in each square of Spidlewood. From there, one or both of the factions will probably attack us, either pushing us back into Merry Meadows, or we'll win, in which case I propose we take over/destroy Lobster Town, and try to blockade the Temple of the Sea. If we need reinforcements, the Crownbreakers can easily send some over towards the temple. If they try to break the blockade, we keep them contained with 2 people in E5, E6, and F5. If Revenant sends help for them, we have the Crownbreakers send reinforcements to hold the blockade, and we fight them off in Spindlewood.