OK. But none of our defenders are very good at the fundamentals of top level defending on a consistent basis, other than Ben Davies in my opinion. Our first choice full backs are both wing-backs bought with Conte's system in mind. Porro in particular is prone to leacing positional gaps down that flank and stands off his man too often.
VDV has pace and he is good on the ball bringing it out with his charging runs. But he is IMO suspect at tight penalty area defending like making, he gets turned too easily IMO and he isnt the best in the air at times.
With Romero - its all there on paper but his concentration over a season isnt good enough. Fundamentally for all his decent work he's single handedly cost us a goal or a game at least every 5-6 games, whether its daft red cards, or switching off and losing his man or the rash lunges that leave our defence completely exposed.
Now you can say "well all players have flaws" most defenders in the PL are hard to get past, hard to unsettle, positionally intelligent and have high levels of concentration. Ours....dont.