From what I understood the overarching antagonist is the character who begins the main antagonist's journey but I don't think Joe Chill had any influence in Ra's al Ghul
Overarching antagonists can also cause the hero to be the way she or he is (such as Joe Chill causing the existence of Batman or maybe Primus creating the 13 Primes because his brother Unicron wanted multiversal destruction if that counts).
Overarching antagonists dont always affect the main antagonist is what I’m trying to say.
