Thanks for the auricle photos. It does seem like silliness. Their only value, in my estimation, is in differentiating very similar varieties from one another. If the majority of each of your three Duzce lines exhibit 3 distinctive auricle conformations, then they are indeed distinct populations of the same, named variety. While there is frequently variation in the auricle shape from one plant to the next, and sometimes one leaf to the next, they generally display a recognizable pattern.
As a side note, one year, after priming all but the tippy top leaf of all my plants, I noticed that the auricle tags that remained on the nearly bare stalks had begun to color-cure themselves. I went through the garden with a pair of scissors, and clipped off enough auricle tags to fill a 1 gallon Ziplock bag. After curing and kilning, it came to about 2 ounces of reasonably okay pipe tobacco, pre-blended. My verdict is that the end product is not worth the amount of work required to harvest, cure and kiln it. Too much handling of tiny pieces of tobacco.
Bob