Skill wise Sarfaraz is better and considering he's considerably worked on his fitness post his own dropping, I won't be surprised if he outperforms Rizwan as a keeper.
That said, Rizwan does have the ability to outscore him with the bat but we've never really seen Rizwan do it at Intl levels so that comparison is still subjective. Although Sarfaraz has previously played a few very good knocks (Sharjah Chase, 100 vs Australia in UAE, CT17 vs SL) but his own form, if we go by his PSL and other most recent stints, have been quite subpar.
Overall I would still back Rizwan despite these issues because he's your first choice keeper and Sarfaraz is basically making a comeback but if both players go head to head I think Sarfaraz would outperform Rizwan comfortably.
I am not counting Rohail because Pakistan cricket debuts batsmen and keepers very conservatively so most probably he's just there to gain experience.