I have three books too. I wonder if they are the same. None of them state a specific number of circles.
When I trained at GM Vince Black's bagua, we primarly did two methods. In one, we did three circles each way for each posture. In this method, each circle usually varied from the other. For example in the first circle we could concentrate on being low. The next circle we could concentrate on being long, and possibly on the third circle we would concentrate on being smooth or fast or whatever.
The other method was to stay with divisibles of 8. The number 8 has great significance in ba gua, and I guess that is where it stems from. With this method a circle in one direction would be 32, 40 or 48 steps, then turn and do the other direction the same. The same number of steps was used for both directions with all 8 palms.
There was one other method which was known as the nine palaces. However, it did not follow one circle, rather 9 tangent circles. This method is described in one of the books that I have I believe the title is Emei Baguazhang. It is not readily available otherwise I would give a better citation.