I think part of the reason Wenger would be interested is that Khedira offers a bigger physical presence and is good in the air. Sagna fought and won lots of headers. Szczesny lumped it for Sagna from goal kicks and Sagna also cleared a lot of corners. But I'm unsure of a Ramsey-Khedira pairing with no defensive mid. Vieira had Petit and then Gilberto to cover. This wouldn't be a similar thing.