That's because before Assassin's Creed Shadows was a twinkle in Ubisoft Quebec's collective eye, Syndicate marked the first time players got to experience dual protagonists in an AC game.
In Assassin's Creed Syndicate, this was the Frye Twins: Jacob and Evie. Assassin's Creed Odyssey ... I asked this exactly: why did every Ubisoft Quebec AC game take this similar approach to ...