I like crate training in a way. I don't think it is fair to put them in there for hours and hours during the day and then again at night. Only at night, imo. And maybe an hour or two every once and a while during the day if you are just going out for a short time. I have a pen for when I am leaving Strawberry longer, but when I am home she has free run of the house. And I am lucky...she comes to work with me and has a pen in the back there. She does not have pee pads. Only business outside. I make her bark once to let me know she has to go and I take her out. It is working well so far.
No accidents in a long time. Well, one this weekend when her littermate sister was over and they got too busy playing to remember the rule! Hmmm.
If your okay with Rocky's routine I would let him stick to it and separate them for the day. Just for training and when Piper's training is improved then let them both have the same schedule. If Rocky doesn't have a crate at night then make sure Piper doesn't know it if you crate her...and if you choose to start Rocky on crate at night be prepared for a loud protest!
Good luck!