I think that is a good idea. But after you do a few hundred of them, you can almost tell by guessing.
Here's another little tip. You don't exactly have to follow that pattern. These shapes are approximate. If you have started to tack a beaver on one line, then find you have stretched it too large, let the other end on of the pelt fall back to the next smaller line, and taper the sides of the pelt from one pattern into the next. Conversely if you started too loose, pull the pelt on down to the next larger line. The slight difference in the oval shape of one end of the pelt verses the other end will be of little consequence.
-- Hal