There is something in what Kesh is saying. I've got a str-based archer atm, grinding it up for now, so I have only 11 agi (yes, I know, lol), but I have 7 PD. I've got a heirloomed strongbow, and it does okay... but my real surprise was when I decided to try a nomad bow for kicks. Not only was the damage very satisfying, but it was also quite accurate for short-mid range shooting despite, after wpf penalties, etc, and armour, me having practically no wpf. When I have more cash to burn, I'll also try the Khergit.
Edit: tried the Khergit, it really is great with 7 PD.