Chapo has a good chance, but IMO Locche outclasses him in the long run. Locche proved in the Hernandez fight that he could get in the trenches with a huge puncher and still put on a masterclass. Locche I think was a tougher guy than Rosario. It's close until the late rounds, where I see Locche separating himself and by the late going, he'd be countering Chapo silly.
I think Rosario might be fast enough to reach Locche. I think it could end up a close decision either way, with Locche outboxing Rosario for some stretches but getting rocked and/or dropped periodically along the way.
I think Locche wins a clear decision. Davis and Camacho's defence gave Rosario tons of issues and neither were as good as Locche IMO (albeit, both had better feet than Locche). He has the chin and heart needed to ride out Rosario's best, as well IMO.