Honestly, I think Ennis would have the best chance (based on talent). Ennis has shown the ability to fight from all ranges, his footwork is amazing, best jab in the game, best switch-hitter, and he is the hardest puncher P4P right now. The second would be Spence due to their ability to fight in the pocket (Barkeley and Hagler showed that Hearns cannot fight well in the pocket)/ Thoughts? I think Crawford gets topped Duran style in the second, even though I rank Crawford higher at 147.
Spence is nowhere near as strong or as power as Barkley and Hagler both of them would have over-powered him.
P4P no. Spence bears Barkley. Haglee vs Spence is 50/50. I'd favor Hagler against Spence due to size.
Hagler had a more proven chin and went toe to toe with bangers like Hearns and Mugabi, Spence has never faced anything like that, he also had better head movement and combo punching.