Some people speak as if our defence is lead by immature 18 year olds which is really not the case. Jones, Smalling, Valencia, Young, Darmian and Rojo are either at the wrong end of their 20s or even in their 30s. So if they need a CB to lead them, then we might as well do a clean sweep, bring in an experienced CB and build the defence around him. If so, I don't think that Koulibaly is the answer. First of all he'll cost us a bomb. Secondly switching to a faster league at his age is tricky. Finally there's a huge difference between a smallish Italian side and Manchester United. That's something Darmian, Veron and Taibi can easily testify about that.
Don't take me wrong, we do need an experienced CB. However I'd rather see us get someone on the cheap like for example Toby who'll be available for 25m next summer. Once we have him in place, then we can start building for the future. Rojo, Bailly, Jones, Valencia, Darmian and Young should be shown the door paving the way to De Ligt, Tierney and Milenkovic
RB: Milenkovic, Dalot
CB: Toby, Smalling, De Ligt, Lindelof, Tuanzebe
LB: Tiernet, Shaw