Vayiqra is about the qorban as performed by the person bringing it. Tzav is the qorban as performed by the kohein. These are two totally different things. Each of us live in our own world.
We have a book of Iyov, which tells the story of the tragedies Iyov lived through. But Iyov’s wife? There is no book explaining her tragedy. Nor that of his children. Those would have been very different books with very different stories. Every person impacted by an event is a protagonist in and of themselves, and Hashem insures that their experiences and duties make sense for them within their own perspective.