To its credit, Marvel has cast a wide net in trying to attract top-tier talent, a strategy that is surely welcomed by its actors and that provides the theoretical prospect of bringing fresh insights to its formula. The reality, though, is a director’s ability to shape such material has its limits. And while “Eternals” sought to stretch the Marvel template, the mixed reactions to the movie — from fans, based on early reactions, as well as critics — underscores that challenge.The Marvel name comes first on its releases for a reason, and along with “Star Wars” and DC represents a specific brand of muscular, effects-driven filmmaking that makes it difficult to put a unique stamp on projects.Martin Scorsese caused a stir when he dismissed Marvel movies as not being “cinema,” sounding both snobbish and a trifle disconnected from the current reality of the movie business. But the director was accurate to the extent that these films operate within certain parameters, which doesn’t support the additional leap that just because something’s popular means that it can’t be good.Arguably, Lucasfilm made a misstep when the studio enlisted three different directors, initially, to oversee each installment of the most recent “Star Wars” trilogy, running into a buzzsaw in trying to accommodate those separate visions.Historically, as the website Rotten Tomatoes noted, having a single director has its advantages. In this case, the result finally left fans choosing sides between J.J. Abrams’ take in “The Force Awakens” and “The Rise of Skywalker” (after he replaced the original directing choice) and Rian Johnson’s in “The Last Jedi,” as opposed to the more cohesive narrative that would have come from a guiding hand working with the studio from beginning to end.The circumstances were different, but the whole “Release the Snyder Cut” campaign regarding “Justice League” can be traced to a clash of sensibilities between Warner Bros./DC Entertainment and director Zack Snyder over his approach. (The studio is part of WarnerMedia, as is CNN.)Snyder left the project after experiencing a personal tragedy, but subsequent interviews have indicated creative differences existed before that, with former Warner Bros. executive Jon Berg telling Vanity Fair, “My job was to try to mediate between a creator whose vision is instinctually dark and a studio that perceived, rightly or wrong, that the fans wanted something lighter.”Again, these movies diverge from what Scorsese considers true “cinema” in one key respect: Marvel and “Star Wars” represent vast franchises, which inspire TV shows and theme-park rides and sell merchandise to feed back into the coffers of corporate parent Disney. Those dynamics turn each movie into a piece in a larger puzzle, one that establishes guardrails on a director’s input.Marvel chief Kevin Feige and Lucasfilm’s Kathleen Kennedy serve as the principal architects responsible for those interlocking parts — Kennedy has called the “Star Wars” story group the “guardians of its timeline” — charting a course that’s bigger than any one film or streaming series.Following those marching orders might not be for every filmmaker, but at this point nobody can plead ignorance about how the system functions, which requires taking directions as well as giving them.When it works, the relationship has its mutual benefits. Marvel made Zhao’s Oscar win a part of “Eternals'” promotion campaign, clearly taking pride in the connection. Directors associated with smaller films receive the opportunity to exercise different muscles on something that will be more widely seen and lucrative than a carefully polished independent gem.Still, there’s an old saying that goes, “If you take the king’s coin you give the king his due.” In modern movie parlance, the related maxim would be when you take the Mouse’s money, the big cheeses there, ultimately, are the ones who call the shots.