Kbug - Don't know why, but two upper full battens is a trendy option suggested by many sailmakers. I'm thinkin' they should all be full length for optimum sail shaping. The full battens have the benefit of being supported by the mast, and can, therefore support the roach easily, plus they play an important role in shaping the sail, and sail shape should best be horizontally oriented. Conventional battens need to be perpendicular to the leach to best support the roach. I'm sure that you would have gotten a little resistance had you requested that the lower two be horizontal as well. The next time you're on the water take note of the sails using full-length battens on the top two positions and you'll see that they are all probably the same as yours. Most technical advancements look goofy until you began to appreciate their function.
IMO the very best set up is a loose footed sail with full length tapered battens. You can control sail shape with your outhaul, and the taper keeps the max chord depth in the correct location. However, tapered battens are hard to find because they are labor intensive custom built and therefore expensive, and aren't promoted by sail shops. Fortunately for our humble craft, such an expensive performance option makes little sense.