The Marvel Cinematic Universe is a well-oiled machine at this point, consistently treating folks to new content in theaters and streaming with a Disney+ subscription. But while folks who spent years watching the Marvel movies in order have been treated to the shiny final product, actually making each upcoming Marvel movie is far more challenging. And The Russo Brothers recently got real about how difficult it is to please all of the A-listers involved in the Avengers movies.What we know about Avengers: Doomsday is limited, but moviegoers are hyped that the Russos are once again behind the camera. During an interview with CBR about their work on Infinity War, Joe Russo spoke about a unique challenge to the crossover films: making sure that the cast is happy. In his words,It's combing through, grinding it over again and again obsessively for the two and half years that we're working on on that project to make sure that he's happy. And Hemsworth's happy, and Holland's happy, and Evans is happy and Scarlett's happy. And everyone feels fufilled. Honestly, I never thought of this. Since The Russo Brothers filmed Infinity War and Endgame back to back, I assumed that the biggest challenge was the mere scope of those movies, and the scheduling puzzle that it must be to get the cast together. But the directors are also careful to make sure that the starring cast feels good about their character's stories, and that the titles are fulfiling for the talent. Is anyone else's head spinning?Luckily, The Russo Brothers are accomplished filmmakers who are behind some of the best Marvel movies of all time. While they bring spectacle and action to projects like Captain America: The Winter Soldier and their Avengers flicks, they're rooted in emotionally-driven stories. And I have to assume that's a big reason why the cast was able to feel a sense of accomplishment and pride in their work.(Image credit: Marvel Studios)Joe Russo's comments have me thinking about the size of the Avengers: Doomsday cast. If it's hard to make sure all the actors are happy, then it must have been even more challenging for their next blockbuster. After all, there are entire teams of heroes in the movie, namely the Avengers, New Avengers, Fantastic Four, and the OG stars of the X-Men movies. Add in the return of Robert Downey Jr. and Chris Evans, and that's a ton of characters to service and actors to keep happy.Of course, The Russos have lots of goodwill from both the actors and Marvel fans thanks to their acclaimed work on the shared universe so far. Still, reading the above comments are sure to alter the way I Watch the new Avengers movies.Avengers: Doomsday will hit theaters December 18th as part of the 2026 movie release list. For now, fans can re-watch the Russo Brothers' previous MCU credits over on Disney+.