Sadly, no. In this very specific scenario the genocide was kind of forced. I mean, the world could just have chosen to leave eldians alone and they already submitted by moving most of their people to an island after realising their mistakes. If the world didnt poke them so much with pure titans and didnt break their wall, which caused genocide on its own, eldians would probably just leave them alone. After the first attack on marley, the world at least in erens eyes changed to the point where no matter how much of it is left, the majority of the people would want eldians all dead. That in my mind caused the them or us situation, where one of the sides didnt need to attack the other in order to survive in first place