with how much HP do you get into the encounter? do you lost civilians on lack of rations? with how many token did you start chapter4? we did it yesterday too. we had 7 civ token and 17 food. we dont eat both breaks and all sufferd 2 HP, also our ursus lost 1HP to an deepwood event. so we get into encounter with 3,4,4,4 on ursus,penitent,cur,ranger. we managed to get all 12 civs rescued but ursus and penitent get down. so i think dificulty came for us through loosing HP in storymode.