OUTSPOKEN: This is almost a question of political theory but we can approach it like a sport question: is team spirit needed for victory?
That really depends on what sport you play.
Boxing vs Football
For football, the epic 7-1 victory of a solid German team over a bunch of Brazilian football stars in the recent World Cup semi-finals is the best case in point. But if you play badminton singles, what team spirit do you really need? You don’t have a team mate to start with.
But even individual sports rely on team, just that we don’t see it. Consider boxing. We only see two boxers fighting in the ring, but behind them there is a substantial support team: trainer, promoter, manager, cutman, second. http://how-to-box.com/content/building-your-boxing-team
Then, the question can be perhaps more accurately rephrased: can the lead player dominate the team?
For our example of boxing, the answer is clearly yes. People pay to see him fight. To analogously put in political terminology, he enjoys a direct and personal “mandate” from his fans. He can therefore choose the members of his supporting team. He can pick anyone for and sack anyone from the team. The team is his. Period.
This is clearly not the case for football. Football is played between teams, who represent clubs or nations. A football captain does not own a football team. He merely leads it. No matter how much fans may like a football star, their “mandate” is invested collectively in the club or the nation, and only indirectly in the players. No one – not even the captain – can claim a permanent role in the field no matter how much he is well-liked by the fans.
This comes down to the logic of the game. Football is a team game and needs ideally 11 players, not one. No matter how great a football star is, he does not make a team in himself. Hence, he cannot dominate his team at whim. He can only lead them as a team.
Presidentialism vs Parliamentarianism
Now coming back to politics, are there different types of government that are as different as boxing and football? You bet.