We install them. Hundreds of them. I'm not going to bother making a pdf for you saying that.
If you don't believe someone that has installed hundreds, then you might as well pick up the 10" rough and have it set out 2" from the wall.
Free advice is given freely, but I'm pretty busy to be making diagrams of things I've been doing for years.
I know what works from experience, if your handyman needs documentation for something as simple as the installation of a toilet, perhaps he's in the wrong field.