there are basic design parameters that have been posted many many times over the years in the various magazines.. you can tweak the looks of everything else and still have a very good flying plane.. If you look at all the "sport" arfs today that is exactly what is done... They all look the same except for cockpit placement, wingtip shape, tail shape.. etc etc... Hlaf the stuff coming out of great planes is all the same plane.. but people buy it anyway.