Yeah, it's all depending on cultivar, and "position in the garden", as to how soon they need dividing. Some can go "forever", before they get too crowded, and are almost 'self regulating", and others, like they said, every other year isn't too often.
As to cutting the fans....yeah, in the fall / early winter, I like to cut things back to about 6".....I use the string trimmer.....anything 'newly planted', I just "leave be" until spring, as I don't want to chance popping them out of the ground. My thoughts are ,the tree leaves, trash, etc. that blows around all winter, will "blow right through" the beds, and not "stick" there, acting as a mulch. But I don't cut fans until the "growing season" is over...plants need leaves to grow, so why would you rob them of leaves in the middle of growing season ?
