There really isn't any real rules of how quickly you work the steps. Just that you work them as honestly, thoroughly, and with as much willingness as possible. That step a year thing sounds like the ideas of a few members rather then the program of AA.
The time it takes me to work the steps is the time God decided I needed to take. If I ever decide to work, skip, half a$$ any of them , that's not Gods decision that's mine. And from experience I already know what happens when I try to work the program my way.
The BB can seperate what the right way is and the ways of other people that think there way is better. You can find the people in the fellowship that do the steps the right way by their actions.
Tom