Actually, the one guy I was talking to said exactly the opposite of what you might think, and he's experienced in fighting southpaws. He said Mosely should circle to Pac's left, because that effectively eliminates the right hook as a good weapon.
Pac being the fighter that he is will come right after him, and he said Mosely should wait for him to throw that left hand, step back and out as soon as he does, and then counter with a hard right hand and catch Pac walking in.
Make no mistake, Mosely's main weapon will be the straight right hand, and if he's got the speed to lead with it and land it, he's got the corresponding power to take Pac out. This is the guy who wobbled Mayweather and demolished Margo... he's got that power.
Pac is gonna wanna mix it up- so is Mosely. That's not a good thing for Pac, because Mosely has taken beatings from way bigger guys and not been KO'd.
Of course, there's still Pac's speed, and whether or not Mosely could pull off the plan even if he implemented it.
I see this fight as more even than most namely because of Nazim Richardson's training methods and strategy. But I still would put my money on Pac at this point. He's so damn fast.