Arthur's intentions were clear. As he exposed the enemy's dirty plans ahead, why not use the plans to defeat them?
He knew if he acted in another way, then his enemy would be alarmed. That was the drawback of having such a sneaky and cautious enemy to fight.
'Ding! Do you plan to let them approach the empire?' the system asked in doubt.
"And might also let them in," Arthur evilly said, "if I attack now, I'll hit a couple of these bases. But most of these little birds will fly away. Who knows what that enemy will do later on."
'So you want to kill as many of these as possible?' the golden dragon asked just to make sure he perfectly understood Arthur's aim here.
"No," as expected, this wasn't Arthur's goal from the start, "I'm going to capture as many islands as I can before destroying the rest."
'…'
'…'
'…'
His words silenced the three beings in his mind.