The Question and Answer section for Macbeth is a great resource to ask questions, find answers, and discuss the novel.
Duncan is portrayed as a trusting King, over trustworthy, who takes care of the people he thinks are loyal to him. He is quite impressed with the Captain description of Macbeth in battle.
O valiant cousin! Worthy gentleman!
The sergeant has related how Macbeth and Banquo fought the Norwayens and, almost single handedly, thwarted both treason and occupation of Scotland. We learn how Macbeth with "brandished steel" fought his way to the traitor Macdonwald, sliced him...
This really is asking for your opinion rather than mine. What would you do?