An Archer doesn't need any strength at all. Both Dexterity and Luck increase your base damage as well (though not by as much as Strength does).
Every 5 points spent in Dexterity increases your base damage by 1.
Every 3 points spent in Luck increases your base damage by 1.
(Every 1 point spent in Strength increases your base damage by 1).
So don't be afraid that your base damage won't increase if you don't add Strength. I think many people are confused by this, thinking that their base damage will be horribly weak if they don't add Strength, which is not the case at all.
With a Luck build, you really don't rely on base damage very much, it's mostly critical, but when you do hit for just regular damage it still does plenty of hurt.
I have tried both a Strength and a Luck Build (1 Dex, 4 Luck). The Luck build is vastly
superior to the Strength build. After seeing how much better the Luck Build is, I deleted the Strength Build and I will never play one again.
Listen to what these guys on the forum are telling everyone, the Luck Build is the way to go