Tony Stark's Iron Man plays a key role in Spider-Man: Homecoming, but originally the Avenger wasn't the only one to show up.
New concept art from Homecoming shows that the Staten Island Ferry scene originally featured two additional Avengers. The original features Iron Man racing to help Spider-Man keep the Ferry in one piece, but the art shows that Vision and War Machine were part of the original treatment (via Reddit's Malcolmflex895).
As you can see in the art below, Vision is shown hoisting a car up out of the water, while War Machine can be seen helping Iron Man weld the holes in on the ship's side. Spider-Man does an admirable job at keeping the Ferry from splitting apart, but it ultimately takes the strength of Tony's suit to bring it back together, welding it into one piece again.
While Iron Man is featured in the film, he never overshadows Spider-Man. It was important to keep the spotlight on Peter Parker, and adding in a few more Avengers to the mix would have been great visually but really doesn't add anything to the narrative. Inf act, it lessens the whole father son dynamic Stark and Parker already have in spades, so it sort of makes sense why the studio opted to leave it just the two of them.
You can find the images below, and the description for Spider-Man: Homecoming is below as well.
A young Peter Parker/Spider-Man (Tom Holland), who made his sensational debut in Captain America: Civil War, begins to navigate his newfound identity as the web-slinging super hero in Spider-Man: Homecoming. Thrilled by his experience with the Avengers, Peter returns home, where he lives with his Aunt May (Marisa Tomei), under the watchful eye of his new mentor Tony Stark (Robert Downey, Jr.). Peter tries to fall back into his normal daily routine – distracted by thoughts of proving himself to be more than just your friendly neighborhood Spider-Man – but when the Vulture (Michael Keaton) emerges as a new villain, everything that Peter holds most important will be threatened.
The cast includes Tom Holland, Michael Keaton, Zendaya, Donald Glover, Jacob Batalon, Laura Harrier, Tony Revolori, Tyne Daly, Bokeem Woodbine, with Marisa Tomei, and Robert Downey Jr. It also includes Jon Favreau, Martin Starr, Kenneth Choi, Michael Mando, Selenis Leyva, Isabella Amara, Jorge Lendeborg, Jr., JJ Totah, and Hannibal Buress.
Guardians of the Galaxy Vol. 2 and Spider-Man: Homecoming are in theaters now, followed by Thor: Ragnarok on November 3, 2017. After that Black Panther debuts on February 16, 2018, while Avengers: Infinity War hits theaters on May 4, 2018. Ant-Man and the Wasp is slated for July 6, 2018, followed by Captain Marvel on March 8, 2019.
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