I think you would be better off having the leadouts far enough apart to not hang up, than having them different lengths. That would be a big headache I believe. I like to keep all of my stuff the same length if possible. I mostly only fly combat aircraft though and we hook our lines directly to the bellcrank. No leadouts required.
Also, I generally setup my leadout location so the fuselage is parralell to the ground. This is sufficient for proper line tension (which is the main reason in determining the location). If the plane is yawed extremely away from the circle this can create unnecesary drag and can actually create too much pull. Depending on the aircraft, you can get your arm tired. I prefer mine to be a little lighter. This is personal preference though.