Dybala is not a cam, he's an ss
Zaza is not an ss he's an st
Draxler is not an ss, he's a winger or should be
Khedira will offcourse bench pereyra
if we get draxler, we should play 4231 with draxler, gotze and dybala behind moradzukic
Dybala interestingly said that in Argentina, while on youth setup levels and also on professional level at Instituto, he used to play as an AM. He said he became a CF at Palermo, but he's familiar with the position and would be glad to be a CAM.
Yes, Zaza definitely isn't an SS. But being mobile, he could work decenly with Mandzukic I believe.
Draxler does seem to have needed tools to be an SS, I don't see much difference there.
Khedira will probably start and bench Pereyra, because of his reputation and salaries.
But I really like Pereyra as a CM and I think he has potential to be world class at that position, he's just great there. As close to Vidal as it gets. He should have the starting spot IMO.