He's telling them to play man for man in defence, similar to Bielsa with Leeds, and that requires a very high level of individual athleticism from every player on the pitch....something we certainly don't have.
That's why there's gaps everywhere, teams will use decoys to drag key players out of position and isolate slower, weaker individuals. Look at the way Olise waltzed past Casemiro and then was able to run 30 yards to shoot at goal from inside the area without being challenged. Look how Mateta was easily able to isolate Evans.
If you have old and slow players, you need to drop the line and play with a very tight defensive structure - what we're doing is the total opposite