I've always just gone to the range and shot the flags and estimated distances in between. I imagine the margin of error on this + range balls makes your suggestion a significantly more accurate method. Thanks!
I agree with everything you said here, but I'm not sure what I would drop my GW in favor of. Even if I'm comfortable hitting a soft PW or a bump and run to fill the gap to the SW, why wouldn't I want a "specialty club" that could give me more loft to reach greens that I'd have to crank my SW (at high risk for me) to get to?