When I demoed them at David Lewis Audio in Philadelphia, he said that the movable head was specifically to make it EASIER to fine tune. IFRC, the advice was that regardless of when the speakers get placed, fire the bottom cabinet straight ahead and angle the tweeter/mid cabinet directly at the sweet spot. For general placement theory, Richard Vandersteen did a nice write up years ago that many use as a guide, for any dynamic speakers. Should be easy to find on Vandersteen's site or elsewhere. The 1/3s and 1/5s concepts that you have heard referenced are part of that approach. Cheers,
Spencer