Well, my experience is that cats will work it out one way or the other. Sometimes it isn't pretty and you must intervene but when you are not there, they all get the picture on their terms. If the younger ones need to respect the older cat more, then so be it. I have tried to modify my cats somewhat, but in the end, it is a waste of my time. They have to work out the top banana thing on their own.

Maybe you should reward Muffin for good behavior....when she is nice to the other cats...... not that you don't already do that.

Just remember, cats are NOT humans and they don't think the way we do.