If Nobumori had died, the person who had been directing the battles against Takeda and Hongan-ji Temple would have been missing and there might have been a possibility to disrupt the battle lines.
信盛が死んだ場合、対武田戦・本願寺戦の指揮をとる人物がいなくなり戦線に混乱を招く恐れがあった。