I've got a +3 longbow and +2 bodkin arrows, and not 2 hours ago I shot a tank in the head + 1 in the chest and he survived.
Believe it or not, it just happened.
I assume he was a high level with lots of ironflesh and loomed armor, and of course these events are rare, like 1 in 20. But what would high damaging archer builds be, if they didn't reward skill?