Fan Casting DCMU: Chapter One

What if DC already had a perfect Cinematic Universe that began before the MCU so this is gonna what happen I will use structures of original movies and genres and animated movies and shows so everything that was released before the mcu was also released in this timeline there is no dark knight trilogy no arrowverse no tv series no DCEU just one universe called the DC movie Universe or the DCMU whatever you wanna call it so instead of phases there will be chapters and this is chapter one