It could have been done, for fun. I have read enough material about the "great" gunfighters, and the typical Hollywood scenario that we see in every movie, was in fact rare. Some of the names we recognize, John Harding, shot in the back of the head through a dark door way, his killer, John Selman, he was shot in the dark. Hitchcock, shot through the back of the head playing cards, and Billy the Kid shot in the dark. His last words were "quien es?" That is, who is it? Pat Garret was shot in the back while urinating. I did read Pat Garret's book on Billy the Kid. Billy and a friend were on foot, but managed to be picked up by two Indians who were going to town to trade. These Indians had goods and extra horses, on which they let Billy and his friend ride till they got into town. Billy and friend did not have any money, but wanted the Indian horses they were on. The two of them dropped back, and shot the Indians from behind. By doing so, they acquired the Indian's trade goods and horses. These are the psychopathic types that movies make into hero's.
The psychopathic killers back then, took every advantage they could to kill, they did not want a fair fight. They would bushwack their victims. These guys were not knights errant jousting in some tournament, they were killers who made sure they had the advantage when they struck.