What you're overlooking is that many of the photos you mention were probably done with medium- and sometimes large-format cameras. With a 6x7cm camera, a 180mm lens gives an angle of view/magnification comparable to an 85mm on 35mm format--even at f5.6 or 8, the DOF is still quite limited on the 180.
The shot below of Renee was taken with a 645 using a 150 and 2x teleconverter for an effective focal length of 300 and aperture of about f8 or 9. This is a tighter shot than what you're talking about, but here you can see just how shallow the DOF is with longer lenses (notice that the hair is back is already out of focus).
Another solution would be to use neutral density gels on the strobes or camera to get an aperture of f2 or so with lenses for 35mm.