Anyone who thinks the series should start with content from the fourth book is someone I don’t think should be trusted to make the series. Susan is supposed to be this mysterious figure for half the story, we’re not supposed to meet Cuthbert and Alain until after we know Eddie and Susannah so that we can appreciate how his new Ka-Tet echoes his old one. But everyone who adapts it insists for some reason to start with these characters and ruin all of that.