Along the back of my house there is a gutter approximately 20' long. The lower end is coming away from the house. A couple of years ago I replaced several of the old gutter nails with gutter screws. ...
I have a situation similar to this photo (except my "dormer" is 24 feet long), focusing on the upper gutter: I think it makes the most sense to catch rain/debris from a roof valley in the main gable ...