I agree the cats will take care of themselves and everybody will naturally find their places in the pet hierarchy. Sierra torments the heck out of my cats. She has since day one in our house and it will be year tomorrow since we brought her home. Oscar just hisses, smacks at her and runs, Gina actually seems to enjoy the attention. She'll squeak like crazy and then suddenly hiss and smack Sierra's face but then a second later, jump up to rub against the dog's face. I've stopped trying to correct Sierra. She is a littel rough, but I think it's just because she's a big oaf who doesn't know her own strength. You may want to consider giving the cats a safe place if you're very concerned. My cats know that our bedroom is their safe place. Sierra isn't allowed in the bedroom and the cats know they can run there if the dog gets to be too much.
Hopefully Noah is a little smarter than my blockhead...Ou r outside cat, Angel, has her claws (the other two don't) and she has nailed Sierra a few times. The dog came running up to me one time outside and shoved her bloody nose in my hand, I figured out why she was bleeding and as soon as I let go of her collar, the idiot ran right back to cat and starting harrassing her again. She'll never learn!
I would watch to make sure Noah doesn't get too aggressive with the kitties, other than that I wouldn't worry too much.