The Goat Head was a dangerous fellow, Duncan had known this from the start—not only because it was an anomalous entity with an unknown background, but also because it had been loyal to the real Captain Duncan and even now, continued to operate and think according to the old rules.
In the Goat Head's perspective, City-States on land held no significance, the mortals within them were laughably ignorant, the weak City-State fleets were mere fodder, and plundering and killing them… was a "routine" rightfully owed to Homeloss.
Duncan didn't know how long it would take to adjust the Goat Head's way of thinking, but he knew the process had to be subtle—using some reasonable explanations to change his and Homeloss's modus operandi was the safest approach.
He took one last look at the Goat Head quietly standing by on the navigation table, having confirmed that it had taken over Homeloss's sails and steering system, and then pushed open the door to enter his cabin.