I don't really have a problem with how we're set up defensively in open play, every set up has weaknesses and sometimes our CB's get exposed, but the opposition still needs the quality to make that happen.
As for set pieces, our biggest problem is a lack of players who can head the ball. We only have Romero and Richarlison and the latter wasn't even on the field during those two goals.
Before today, we conceded 12 goals from set pieces which was 2 behind Villa, our main competition this season. Most teams have conceded around 10 this season.
Get players who are good in the air and it won't be as much of a problem. It really is that simple.
Dragusin was bought with this in mind.
Aerial duels percentiles (fbref):
Dragusin 88
Romero 82
Udogie 48
VDV 20
Porro 10
But Drag doesn't look to have the all round game to displace VDV or Porro. So really we need VDV to improve and get up to something like 50th centile. And given his height, that should be possible.