I had heard this too, and I agree for different reasons. More on this in a minute.
I don't think this actually happens. No matter how much you practice classifiers, there's no way you can consistently shoot 95%+ without legitimately having top-tier stand-and-shoot skills. I think so-called "paper GMs" are a result of either a) people who *only* practice stand-and-shoot skills and neglect movement & stage planning, or b) people whose clubs let people re-shoot classifiers so they keep playing 'til they win.
The reason I feel that the FAST Test is a poor drill is because there's too much going on. You've got a draw from concealment to a smaller target, a split on the smaller target, a concealed slide-lock reload, then 4 quick shots to a -0 at 7 yards. That's so many individual skills that I don't think you'll get any better at each one if all you do is practice them all together.