Ace was being selfish as well. Again, WB told him to leave Teach alone. WB was Thatch adoptive father and knew him for way longer. Ace did not consider this in his thought process.
His hubris lead to the MF war, the death of his father, several siblings and the mental traumatization of his brother
His hubris lead to the MF war, the death of his father, several siblings and the mental traumatization of his brother
ace was acting on impulsiveness not knowing outcome
itachi did a cold blooded assassination of his clan with a calm mind and knew what's gonna happen next
certainly not the same thing