I'm going to ALWAYS advise against some recommended loudspeaker location recommendation layout in an owners manual, as there's simply too many unacounted for variables to consider for best results. Each layout and seating situation is different. Bottom line is loudspeaker / subwoofer placement in the room for any given room layout and seating locations, acoustics, etc, is going to vary greatly. And while some owners manual or recommended setup in a book can give you a rough idea, you still need to find the main seating location, and set speakers and subs according to those first, and then plot other seating after that. Then measure and listen for all, and maybe make tweaks and adjustments.
Never follow some random piece of literatures setup instructions for your space! Your ears are final judge - but measurements will always need to fall somewhere near accurate for good sound and performance. -especially when it comes to bass response! EQ the rest...