Scooby_Simon, been a while since high school physics so please excuse the cloudy brain whilst i remember, but are you considering the calc as a 2nd class or 3rd class lever? If 2nd class, then you are correct, but I always thought as 3rd class. The crew is the lead weight lump at the end of the wing/lever pushing down. The force from the sails/wind/mast is on the middle of the lever pushing up. If you can move this force point closer to the point, the more effective the force pushing down.

Am i missing something?