Pardon me for saying so, but this seems like an incredibly dumb way to solve this problem. The example they use is the SG, which, in my opinion, has a body that's slightly overweight but not as bad as most guitars, and a neck that's massively overweight. So their solution is to make the body massively overweight in order to compensate. That's like losing a foot in an accident and then cutting the other one off to cure the ensuing limp.