My understanding is that kokyu ryoku is everything. If you can catch it aikido becomes so easy and so simple. Well that's what the top aikikai teachers used to say. So compared to that shuchu ryoku and chushin ryoku are just technical details and you know what they say about the small stuff.
Lift your arm, smile (optional) and throw. That's all.
Kokyu ryoku does NOT come even close to covering everything enough to afford you the cavalier approach of "Lift your arm and throw." Ueshiba's movement displays a deeper understanding then that.
There are ways to train and then there are ways to train...then there are ways to use the results of that training that you will never learn from breath training alone. Thinking it does will limit your growth. More importantly-meeting someone more fully developed will see you stopped in your tracks. With more fully developed practice and understanding, you can get to a point where you would not be a "push over" -even for an expert. TJMA aiki movement with breath power will not get you there.