That may have been me, Blazin - I posted some stuff on hormones recently. Only growing leaves produce hormones, and they're mostly produced by the growing tips. Those auxins encourage root growth as well as discourage lower leaf growth. Cutting fans has little effect on root growth in cloning, and it reduces transpiration through the leaves, giving the plant more time to root before it dies off.
Auzins come mostly from the new tip growth.
And that's the scientific truth! Cutting fan leaves in half means the plant has less green material to keep alive without roots. As long as the growing tip (apical meristem) is intact, all the auxins will be present, including and especially the rooting hormones. Add a dip of rooting hormone (clonex, etc.) and now you're taking cuttings the proper way.
I cut mine down pretty far....and they grow one or two sets of new leaves while in the cloner! It's very, very easy!