Romero = Mignolet ( I guess you are going to sign Cillesson - *spelling* - in which case he'd edge it. Ming was much better over the 2nd half of the season due to changes made in the way he treated specific situations, however most people remember the 1st half).
Darmian << Clyne (Darmian has it to prove in the PL, both are internationals).
Smalling = Skrtel
Rojo = Sakho (I believe Skho has a higher 'ceiling' if given a run in the team).
Shaw = I think Gomez is taking over that slot and if his PL performances are anything like in the friendlies and in the Championship last season, then he could be better).
Schweinsteiger > Lucas
Herrera = Henderson (totally different players, it would be hard to convince me either is better than the other since their individual talents are so disparate)
Schneid < Milner (I guess it's because Schneiderlin now plays for United he is being rated higher
though essentially totally different players again)
Mata < Coutinho (all day every day for me, the little magician. Always liked Mata but he far less consistent than Coutinho and can disappear completely from some matches)
Depay = Firmino (who knows)
Rooney = Sturridge/Benteke (I rate Rooney as a striker, however currently at Sturridge's level (when he's fit) ? Naaah. Benteke we'll have to see.