A difference between 7-8 might not be noticeable though. Perhaps a larger number variation would be more so?
I have heard conflicting views on the PD accuracy effect from so many different people. So it's not entirely clear.
What is clear however is that if you're to do any kind of damage in CRPG with a bow, you need at least 5 PD with the Strongbow. Taking a Strongbow (1 slot) allows you space to take 2 sets of arrows and a 1h. Useful on the ground. The higher end bows limit this with their 2 slots. So honestly it depends whether you want to make a decent hybrid or a pure dedicated archer. A dedicated archer will use the high end bows with all arrows, no melee weapon there. A hybrid will use the strong bow, or take a 1 slot weapon with only 1 slot of arrows with a higher end bow.
Finally, if you're making a hybrid, I'd aim for nothing less than 130 wpf in a bow. Anything less and it's simply to inaccurate and frustrating. The higher the better in this case. I can put up a decent fight with my 1h Espada with no wpf or power strike if I need to. You won't last long, after a few blocks the speed difference is to noticeable, but it can allow you to get out of some sticky situations. But with 130 wpf in bow, that would give you a bit of leeway to put some wpf in either 2h, polearm or 1h depending on your choice. If you want to go pure, then don't put wpf in anything other than archery.