Having a noble education doesn't mean being smarter, she could have all levels of education in strategy and etc... but smartness is something innate, and it can be honed with experience, a kind of experience easier to be acquired on the streets than in the middle of the nobility. Besides in the end where he drugged her, he could have just killed her and abandoned her body in the snow, knowing she's dangerous that would be a good option, to kill her and abandon her body in that house they were in, and set fire to the house so there were no clues or evidence, there were several options for Roman's group to win, another good story option was to keep her chained in the house, and ambush her soldiers in the snow and forest.