I think though, certainly in Holgate's chance case he could be as good at right back as at centre back. He's comfortable on the ball, quick, has a decent engine etc.
Football adapts and moves forward. The trend has certainly been towards very attacking fullbacks, but we know Ancelotti is quite an innovative thinker, and he may well be of the view that he wants more power and defensive capability from his defenders, particularly if we are going to be playing a midfield 4 ahead of them containing Bernard, Gomes and a Winger down the right.
There's a lot of thinking allowed for me, but playing behind a midfield 4 you do get tested a lot more than playing with 5 men ahead of you. You have to be able to go man to man with the winger more often.
As for better, yes, that's certainly the hope. I think Todibo is very raw and it may be the case he needs 6 months to get used to new surroundings. It's good though, if those two rock up, Mina in particular and Holgate know only their best performances will do, and merely signing them drives up performance. We would have real power and pace at the back, and be able to implement a completely different game plan. It would make the midfields job much easier too. It all ties in.