You can skip past the fight on the drawbridge. Before you lower the drawbridge, climb the same ladder that Farrah does and return to the mess hall. Recharge your health and use the save point again. Now, run with your weapons sheathed until you reach the next door. As long as you aren't armed, you will be able to bypass the soldiers without taking damage in a confrontation. Once Farrah also reaches the room with you, pull the lever and continue working your way through the game as normal.