I've done three camera installs so far. This is exactly how I did my second and third install, except I added in the entire range of view (88 degrees for my cameras, IIRC).
Personally, I would buy/upgrade to a 16 camera NVR. While you can get a really good idea of what the cameras will capture with the above method, it's very different to actually see what the cameras see until they're up. Having a 16 camera system allows you to include cameras in points that you never thought you would need (I've had to add 1 camera to each system after having all the ones I thought I needed up).
Another tip, when adding the view angles, you don't need all the cameras to cover every single area, I personally put cameras on each point of entry, so if anyone was attempting entry you could see. The backyard, I have a rather large blind spot, I could see people come on to the property, but then they'd disappear (just flat ground) for a while, before showing up at the back patio/pool.
My biggest suggestion is to have a bigger system than you think you need, my mom only has an 8 camera NVR, and we will be maxing it out at her new property, and unfortunately will not have 100% coverage.