Depends on the witnesses. An intellectual like Paul the apostle, who at one time persecuted Christians makes a pretty good witness. On the other hand here is some info about Oliver Cowdery, one of the 3 witnesses who supposedly witnessed the plates of Mormon founder Joseph Smith.
From Wiki's article on the 3 Mormon witnesses
Like {Joseph}Smith, who was a distant relative, Cowdery was also a treasure hunter who had used a divining rod in his youth. Cowdery
asked questions of the rod; if it moved, the answer was yes, if not, no. [6] Cowdery also told Smith that he had seen the Golden Plates in a vision before the two ever met.[7]
http://en.wikipedia.org/wiki/Three_Witnesses#Oliver_Cowdery
Also earlier I talked about how any blacksmith could of made plates. A few websites said Cowdery was a blacksmith by trade.