Also, it seems like the Root/Shaw thing was something that developed organically as the characters got more screen time together, whereas the Root merging with the Machine seems like it's been their endgame plan for a very long time, likely predating the emergence of "Shoot." That's just speculation on my part, though.

Initially I also had this same reaction to how they decided to split up, but then when I thought about it some more, I decided that Reese and Fusco probably both realized that sending Shaw all alone on a mission to find Root probably dead or dying would be a huge risk, especially in her current psychological state.…