I know that you said that he wasn't a great marker, but the fact that he's done very in marking top class players makes him better at marking than you think (for me, at least).
Also, in terms of your claim, I don't think they are that much better. Slightly, perhaps, but not "much". Comparing Coleman and Clyne's marking to Rafael's, I wouldn't say they are even. Both rely lots on their pace to recover themselves and stop opponents. Rafael used to be like that in the beginning, but he's now better than Clyne and Coleman at keeping track of the dribbler and maintaining his ground and stance. His marking is comparable to that of the top 3 that you mentioned.
It's fine that you think he isn't a great marker, but I disagree with that notion.