This discussion overlooks one very important element, the Documentation Package. No plane, regardless of how perfect it might look, will score well if the documentation presented to the judges isn't up to the task. 10 points is not a given. From my experience, most Scale entrants shoot themselves in the foot by providing weak or error filled packages, or they simply don't do a decent enough job of making their model match the material. Even with the so-called perfect plane the documentation needs to exactly support the entered model. Not sorta maybe.
Fun Scale is still a Scale event and needs to be approached in that vein. It isn't Casual Scale or Good Enough Scale. It is plenty possible to build something from Walter Musciano or any number of other sources and do very well. For Fun Scale just choose a more basic subject. You don't need all the bells and whistles. Get the outlines right. Get the color and markings right. The single key ingredient is to take the time to do enough research, make your plane look exactly like the reference material you have assembled, and practice to fly it well.