It was a series of ups and downs for me.
On the upside, I was delighted by the return of Nhan.
On the downside, they put her on the bridge in a situation that completely disrupts the chain of command and causes confusion and hesitation in a crisis situation. Either you trust Burnham to do the job or you don't. Maybe they shouldn't have and gave temporary command to Saru. But you don't put someone there to second guess her decisions in the middle of a crisis to the point where they're actually arguing with each other on the bridge.
Also on the downside, it completely undercut Saru's position as First Officer yet again. He is the one who should be bringing such concerns to his captain in an appropriate setting. I don't believe that he is so attached to Book that he can't make the right call when it's needed.
So the actual pretty cool cat and mouse game was always being undermined by this completely ridiculous and unbelievable (to me) situation of Nhan being assigned to second guess Burnham. It just felt like so much of the typical manufactured interpersonal conflict on Discovery that they do so poorly sometimes.
Data don't play that: