Dentures are not, in fact, anachronistic, and could be found in some form in a fantasy setting. With the high availability of magically strong metals dentures of a quality rivialing modern dentures could be produced. In earth history, there are articles stating that they have been found thousands of years BC, and in some cases, even fanged dentures may have been used. http://news.nationalgeographic.com/news/2006/06/060614-oldest-teeth.htmlGo to Comment
Exactly. It is no more accurate then the original archer, and with a cumulative penalty to hit it should miss quickly. That it cannot distinguish allies makes it dangerous at short range, since the archer could potentially qualify as target.
Not sure how true to the spirit of the 100 word challenge it is to clarify in comments.