IMO, wiring a rack is equal parts experience, training, and art. you can have them read industry mags for visual help, trade shows help too. to be completely honest, as harsh as it may sound, your brutal honesty may be the best eye opener to what they are doing "wrong". in their eyes, their artwork may be great, but we would all be using harmony remotes had someone not shown us the error of our ways and what else was available out there. some guys will always be bad at wiring racks, it takes a level of creativity that some just dont have. but those same guys maybe your best wiring and installation guys.

good luck
proaudio