The phrase "overall arc" refers to the overall storyline or direction of something, such as a TV show, book series, or someone's life. It focuses on the major events or developments that shape the entire journey or narrative. Full definition
Director Ryan Coogler explains that although the performances in this scene are stunning, it just didn't work in the overall arc of the story. (relevantmagazine.com)
She, the writer of the novels, created those character, those stories, and the overall arc of the series. (slantmagazine.com)
Younger clearly has a knack for visual storytelling and each of the performances on display here, with the supporting turns from Aaron Eckhart, Ciarán Hinds, and Katey Sagal standing strongly next to Teller's lead performance, are far more than competent and in fact add heavily to the overall arc these characters experience allowing them to not just remain stock characters. (rottentomatoes.com)