Scylla and Leon had already begun to create a battle plan. The way that the two seemed to get along after having their merfolk and aquatic demi-human forces work together was spectacular. They could somewhat guess what the other was imagining before it was said.
"Fifteen squads will leave and try to surround the main area where the ships will be letting off the remaining forces. This will also protect the ships as they make their moves inside the dangerous area within the island." Scylla knew very well that there could be more threats they did not know of yet.
The ocean waters and the beach were already a place known for threats. The high possibility that they would need to fight monsters while coming to shore or even on the shore was very high. However, it was already clear that the island had some monsters on it.