I am Newbie indoor/hydro/RDWC but experienced with plants. So, take this practical info with a grain of salt. I am sort of a grow and let grow guy and as my crop has developed, I noticed several things about the fan leaves. Obviously, they produce energy with all the surface area. Each large (fan leaf) normally generates a branch. It would appear that the fan leaves force the branches under them to shoot out at near 90 deg angles to the stem (may or may not be a good thing for your method of grow). It would also appear to me that these leaves are very beneficial for dumb asses like me who continually overdose their plants with Nutrients. I think they divert some of that hot mixture from the tops. Take one for the team sort of. I don't like to do much to plants but some of my leaves have been selectively removed to let light in. NOW thinking about your question.... I believe the actual position of the leaves on the stem is more a function of a simple attempt, by the plant, to achieve equal growth, light, and nutrient distribution throughout the plant. Check out some of the morphology, I know fun huh, diagrams on cannabis and some atypical plants might have more info on position and structure. Best of Luck.