And I would assume it would be impossible to constrict an archer to fire arrows out of a small slit in any RTS engine.
*muses* Well, as the archers approaches the slit perhaps the object could be swapped for an object using the same model and skin, however it cannot turn and can only fire in a certain angle - say 4 degrees scope. When the archer is told to leave the object again is swapped for the original, freer archer object. Experience would have to be transferred - ie. this is not worth it!