I wouldn't say he's top 5. Top 10-20 is a lot more reasonable. Jimmy is a great cover corner, but given that the NFL has become a passing league. There's a lot more very good cover corners than there used to be. Peterson, Sherman, Peters, Harris, Talib, Norman, Gillmore, Hayward, Verrett, Jenkins, Trufant, Rhodes, Darby, Amerson, Butler, DRC, Breaux(very underrated), Jimmy himself, Bouye played very well last season, are all very good players who are easily #1 corners who can take on just about anyone coverage wise.
You want to say Jimmy is top 15 or even top 10? fine. You can make that argument. But top 5? That's a hard sell.