Did you say that from the perspective of realism, or the perspective of this game engine that we are forced to use?
If you start adding in-game vectors for wind then you will increase arrow speed if traveling along that vector, and this game has proven that even a small increase in speed lends significant amounts of damage increase.
If we were to add wind direction that slows down or speeds up the deceleration of range while also adding a deviation sideways without adding or subracting speed from that, then it is impossible with this game engine as well as being overly-complex from an engineering perspective.
EDIT: As for real life, shooting with the wind actually does help as much as shooting against it hurts you. However this is not as noticable due to the extremely fast arrow speeds in real life. Since in cRPG the arrow speeds are snail rounds, any change to speed is going to be extremely noticable, and again, this means that the damage is going to be significantly effected. cRPG uses snail rounds, thus any change in velocity will be very apparent.