Archer friendly fire is questionable; it is a matter of testing whether it is best or not. It's easy to implement, we just flick a switch on or off.
Perhaps you should implement a 'hardcore' gametype where friendly fire is enabled?
If wind is incorporated and it can effect arrow flights then perhaps a mage would have the ability to cause a short gush of wind to cause all arrows to alter course? Would be a useful tactic when attacking a fortified city, especially if you had a few mages and could minimise your losses...
Xbox live gamertag: WelshAbyss
Feel free to add me and game to our hearts content :)