I'm no archer, but I'm guessing that 9PD builds will give you more bang for your buck unless you can achieve 5-6 WM like your post indicates. 10 PD is pretty excessive and it's up to debate how many pros/cons they get depending on how much you value mobility. As you said, an 8 PD build will come with more quality of life benefits.
Not sure what you want exactly in terms of specific changes. Against your average 65-75hp infantry, going from 3 to 2 body shots requires an astronomical damage increase, so it makes sense that you'll be somewhere in-between most of the time even with 10PD. Fortunately, they're not at 100% health all the time, allowing you to 2-shot anyone with some chip damage easily.