Those metaphors are sports and war. In fact, the language of war pretty much is the language of sports. But there is one important difference. In a war, all is fair. In sports, fairness is all.
War has no rules.
Sports has lots of rules. Battlefields are rarely level. Playing fields are always level. Business is not regulated by rules of war. Microsoft tried mightily in The Trial to convince Judge Jackson that the computer and Internet worlds were battlefields and not playing fields.