He absolutely doesn't need to engage. Again, take a look a the 2nd clip you posted, this is exactly what he does, he does NOT engage the player at all, he lets him run unopposed, and holds his position, which means everyone else also held their position. The result, the attack is well-defended with all our defenders in front of the goal and marking their man. In fact, in doing this he's slowed up the attacker slightly meaning that Destiny can put pressure on him as he goes to cross the ball (in the example when they scored Destiny is drawn to the wrong man as VDV runs out of position to the player on the ball, this man is even further away from him that the attacker on the ball making it all the more impossible to get to him). The only oppo player that has separation from one of our defenders in this 2nd example is Hudson-Odi, which is okay as he's going to receive the ball at an impossibly tight angle from a ball that won't have pace on it as it has to be lofted across our defenders to get to him, and can do nothing with it (Porro, is well placed to stand him up if Hudson-Odoi chooses to bring the ball down rather than attempt to shoot).
Once VDV is drawn across the pitch we are fucked, end of. It's asking too much of Romero, he's put in a stick-or-twist position. We are asking Destiny to turn into Usain Bolt, there is no way he's making up the ground. As I said Biss is the ONLY player that holds his correct position but even if he too turns into Usain Bolt and comes towards the attacker, then he just cuts the ball back to Biss's man and he'll be unmarked and free in our box running onto the ball with still no defender in place.
Again, I want to know exactly what PEH prevented when he went into that gap, what did he stop? And what did he prevent by dropping into this position? Is he blocking a passing lane? No. did he prevent the cross? No. It's mute because the attacker chose to cross the ball to the back post but with PEH in that gap the attacker is presented with another option, which is to play the ball square or cut it back, if PEH is just 5 yards higher this option is cut off.
Biss was the ONLY outfield player that held his position, whilst everyone else was out of position as a direct consequence VDV.
I'm not dishing out any hate towards VDV, I love the fella, just calling out this goal was on him entirely, it simply doesn't happen if he does what he did in that 2nd example. I'm delighted he didn't engage in the 2nd example, his discipline then was exemplary (you can even see the exact moment when he switched fully on because you can see him change his run, which puts a smile on my face because he knows, he knows not to get pulled out as he did in the first half) and as a direct result enabled our defence to keep its shape and remain in total control and defend the attack making it look so easy.