You know you're right. Of the Klingons we've seen through the ages. None of these (except B'Elanna) had anything resembling anger management issues. You look at episodes like "Heart of Glory", "Redemption", "Once More Into The Breach" which feature numerous Klingons interacting with one another and they all get along as well as humans do. B'Elanna by comparison comes off as having a chip on her shoulder and uses her mixed heritage to scapegoat her behavior.