Knights: Our first display of teamwork actually managed to give her a good deal of trouble. Maybe we should continue to attack together...or not. After all, she's just a single woman, no need to continue doing that, we can just rush her individually, what could go wrong?
I think the backstab IS part of a 'formation' as well.
It seem to be the 3 upfront getting attention then daggers go for backstab, with expectation to either get a lethal hit from that or at least cause enough distraction on the opponent for the 3 up front to come in to cover for him.
But Shurine evade and counter in the same motion, giving the 3 up front no time to react.
Which cause axe to act out in rage, leading to another easy kill.
In the last part you can see them trying for teamwork again with greatsword tried to keep her attention for spear to attack from blind spot.
So there's certainly coordination, but as Shurine said individually they weren't that strong so she could whittle them down one at a time.