Before the 12th amendment, the presidential candidate who got the second most electoral votes became the vice president. This meant they were usually different parties.
It occurred to me that one thing this achieved was always ensuring that there was someone in the room who would be willing to disagree with the president. He couldn’t surround himself with yes-men.
Sorry, didn’t notice the location of the instance. I am talking about US law, specifically the amendment that made the president and vice president elected separately. Before that the VP was whoever got second place for president which often led to them having differing views.