373. If more than one event occurs simultaneously that Replacement Effects could apply to, each event is treated separately and individually for the purposes of Replacement Effects, and Replacement Effects with the same controller are applied in the order of their controller's choosing. Example: Two units controlled by the same player die in the same cleanup. That player also controls Zhonya's Hourglass. They must decide which event to apply Zhonya's Hourglass to first.
373.1. Although these events are simultaneous, the applied Replacement Effects are ordered. If multiple applied Replacement Effects with different controllers would execute simultaneously, they execute in turn order.