Several things:
-- 100% skills and spells don't work 100% of the time. Everyone knows this to
be true. Especially merchants.
-- some projectile weapons are easier to fire at short range than others.
Crossbows in particular are easy to use at point-blank range, which is why
they can be used in the 2nd party row and bows require the 3rd. Therefore,
firing a crossbow in hand-to-hand requires less hop back skill than a longbow.
This would also be true for an archer firing a longbow in the second party row
behind a more traditional tank, as they only need to hop back one spot to be
in the third row.

The skill is fine. Your use of the skill requires some tweaking.

Shinarae Lluminus