Paramount / Marvel
Earth’s mightiest heroes form an uneasy alliance to take on a threat that’s bigger than any one of them could handle alone.
Captain America, according to the comics as well as basic logic, is the natural leader of the Avengers. He’s a pie-eyed idealist with a genuine, if not stiffing, sense of right and wrong. But in the real world, Iron Man is a far more popular character. His films have done better, and received more critical praise than Captain America’s solo effort; so it would have been an easy marketing decision to make him the new leader.
In the end, it’s hard to tell which one they went with. Both Stark and Rogers give orders to the others (and each other) at times, but everyone seems to agree with everything right away; and you can’t see where authority is unless it is challenged.
Iron Man and Captain America’s relationship is contentions; but it works out because they are so separate. Stark is master of modern world, as exemplified by technology and corporate interests; while Rogers is the master of the past, blind faith and self-sacrifice. They have complimentary (that is, opposite) strengths and weaknesses, and thus, despite being larger than life personalities, they tend not to get in each other’s way.
Black Widow and Hawkeye are the ‘average’ members of the team, though by any human standard, they’re ridiculously powerful. Hawkeye is essentially a new character for this film (he had a brief cameo in Thor). He has an interesting story arc in which he is brainwashed in the opening scene, and remains in the employ of the enemy till about the halfway point. This kept us from getting to know the character; but then, it might have been a cleaver strategy to keep the audience from finding out how dull he is. Black Widow’s true super power (aside from superb flexibility) is manipulation. Of course, this is a skill which is only useful in the quite moments; but given the fact that she can’t contribute as much in a fight, it very appropriate.
The Hulk has had a rough road in Hollywood. First was 2003’s Ang Lee directed Hulk, which was one of the least successful Marvel films; then, Marvel got back the rights to the character and produced the next one themselves, 2008’s Incredible Hulk, making it one of the tent poles leading up to The Avengers. That, too, underperformed. But Marvel is sticking with him, and now we have the third actor to play the green monstrosity in the modern age, Mark Ruffalo. Ruffalo has been widely praised as the best Hulk, but I don’t think it’s a fair comparison. The Avenger’s Bruce Banner is at a different stage in his character arc. He has come to terms with what he is and has learned to control it. He doesn’t have to be the manic, fidgety, paranoid man that was the protagonist of the earlier films.
Thor is the connective tissue in the Avengers. His brother, Loki, is the villain, and the source of power he seeks to harness is of his world. The Asgard, the alien race from with Thor and Loki hail are, by any useful definition, gods; and so present a suitably large challenge to justify bringing in the Avengers. Obviously, if it were just Loki, Thor would be able to handle it himself, and so Loki has an alien army of mysterious origin to even the odds in his favor. Thor; after his solo film, is much more refined and kingly this time around. He has matured enough to sublimate himself as a member of the Avengers; no more important than the rest.