Asamoah IS a CM that has been forced out wide, so yes he would happily return. Although, he recently stated that he would play wherever the coach wants him to play.
He has also on several occasions as late as during this WC stated that he do not want to play out wide. Short answer to your suggestion: Yes, it is possible!

Pereyra is very versatile while I have not seen Romulo play from what I've heard it seems like he could play CM.
I don't think Vidal would leave,
I don't think Marotta and co. are that stupid. They know it's big money, but they also know that finding replacement that is equally good or better will be very tough and take much time. Without a plan b, they won't, I hope, do it. I hope that if we for some reason suddenly decide to take the cash that we do not splash the cash on 10 Padoins and hope that 1 of them turn out an average joe.