@Meo A psychopath and a sociopath are not the same thing. Not recognizing the pains of others and/or being indifferent toward those is one of the main points of sociopathy.
Going further, the main point of my comment was that she does not seek to kill for the sake or satisfaction of it. She instead do as a matter of fact when she thinks she needs to. She is not blood-thirsty, and killing all the bandits was indeed what was meant by her superior officer.
Would that officer accepted the surrender of the spear-wielding bandit? Yes, he probably would've and would've tried to recruit him and maybe the bandits too to some extent. However, her killing them anyway is not because she's blood-thirsty, but rather because she's too dumb to adapt to the situation and thus just went through with her initial orders while not caring much about it due to her being a sociopath.