Is he already more important than Romero?
Both important in different ways.
Romero is much much better on the ball. Reason why we're elite on the ball in our own half. You can't press Romero because he'll find the smallest gap and break the line with a pass, hence why he dictates and "slows it down"
Van de Ven is a recovery centre back. And tbh he's probably the best in the world at doing so because of his pace and physique. Not bad with the ball at his feet either, but he's much much safer
Compliment eachother very well.