Fenech would get ****ed up in one of the dirtiest and grueling fights you will ever see. I'd give Nelson a better chance.
Nelson would definitely have a chance. Fenech's style plays into Saddler's hands but stranger things have happened in the ring.
Saddler mauls both these guys. I tend to think Nelson's reputation as some kind of brilliant cagey boxer is puzzling. Even though he's skilled he was mostly a puncher and if Saddler could hunt down Pep and Elorde there's no way Nelson out boxes Saddler and he doesn't hit hard enough to stop the virtually unknockoutable Saddler. I think Fenech's meriless nonstop aggression could give Sandy some troublesome rounds but he was smaller than Saddler and in the end they were in differant classes and Saddler stops him.
The difference between Nelson in comparison to the likes of Pep and Elorde is that he was very durable and physically strong at featherweight, along with his good boxing ability, which would make it more difficult for Saddler to wear him down with his usual tactics. He was not the boxer that Willie Pep was, but stylistically he might match up better with Saddler.