The original six Avengers cover a much bigger real-world height range than the 2012 movie's framing makes obvious. Chris Hemsworth is 191 cm tall in Stand Next To's current supported data, Chris Evans 183 cm and Robert Downey Jr. 173 cm. Current person-specific height evidence puts Mark Ruffalo around the low 170s, Jeremy Renner around 173 cm and Scarlett Johansson at 160 cm.
That means Thor's actor is roughly a foot taller than Black Widow's actor. On screen, costume footwear, blocking, camera height and compositing can compress that difference. A true-scale lineup does the opposite: all six actors stand on the same baseline and use the same literal scale.
This lineup is bounded by the team in Marvel Studios' 2012 The Avengers: Robert Downey Jr. as Tony Stark / Iron Man, Chris Evans as Steve Rogers / Captain America, Mark Ruffalo as Bruce Banner / Hulk, Chris Hemsworth as Thor, Scarlett Johansson as Natasha Romanoff / Black Widow and Jeremy Renner as Clint Barton / Hawkeye. It compares the actors' standing heights, not the fictional heights of Hulk or the other characters.