Except "aging" looks absolutely nothing like roan, so I don't understand why you feel it necessary to label something with a term that has nothing to do with it. Roan has a very definitive definition - it is an EVEN mixture of white and pigmented hairs throughout the entire body. Not a bunch of scattered grey/white hairs from age. Heck, by that definition, my Arab mare is roan NOW because she has a few white hairs.
It's fine if YOU aren't confused by it, but I assumed the purpose of trying to make an educational website was to educate people, not ensure they know all the terms you personally use, incorrect as they may be?