There has got to be literally hundreds of ways of drilling a bowling ball. Offset thumb, CLT, Sarge Easter, Bates Grip, Tri Grip, etc........ and the list goes on.
I believe that, almost like snowflakes, no two human hands are alike. That means that trying to drill holes in a 3 dimensional object in order for it to "fit" anyone's hand specifications precludes the process from having any single solution.
While drilling a bowling ball does require the application of scientific principles, the ART of the actual drilling is in the APPLICATION of those principles, and that is where a knowledgeable, experienced proshop operator can make ALL the difference.
There is no "one size fits all" way to drill a bowling ball, no matter what technique is used. Whether we like it or not, many times getting the desired fit and results are a "trial and error" process, but one that can be shortened, sometimes greatly, by the knowledgeable, experienced driller.