Same discussion on mtb-news.de - @grinsekater is doing field tests with different riders on different bikes to find out more about bike geometry.
Thing is, there are so many different bikes with so many different numbers, and every rider is different too. And a rider can change his body over a short time and adapt to a bike that did not work under him before.
There is no "ideal" body or "ideal" bike for mountain biking, not even for enduro. Maybe for roadies.
Sure, a longer bike will work better on the downs, and if the chainstays are a bit longer on a long bike, you will feel more centered.
But i feel great on my hardtail 29er with a 64 head angle, 475 reach and 75 seat angle, and ultra short chainstays because of the 650B+ wheel in the back. So much fun. The 29 Capra XXL is fun too, but different. But over here there are not any trails that resemble the PNW.