Yes, I think the smaller back was needed. Thus it also resembles a "close fitting sloper" a bit more.
To adjust the paper pattern, just shift the outer edge (armhole and sideseam lines, body and yoke) of the back pattern pieces parallely towards the center back for 1cm. just lengthen the armhole line at the shoulder line till it crosses the original shoulder seam line. (it will be just a few millimeters)
To adjust the fronts, just "clip off" the superfluous length (1cm) at the outside of the shoulder seam, and from this new end point blend in the seamline towards the rounded part of the armhole.