Liverpool supposedly have a weak defence, yet we've conceded 13 goals. There are 9 teams who have conceded more, and 2 teams who are also on 13 goals. Arsenal and Man City are on 10, and Chelsea are on 9. If Liverpool or Man City's defence is poor, then, statistically, Chelsea's don't look miles better at the moment. Chelsea have only conceded one less than City, and have +2 higher GD.
I can't find the stats, but apparently Liverpool's apparent weakness at set-pieces isn't as bad as originally thought. I even heard we've conceded the same amount of goals from set pieces as Spurs, the best defence in the league, who've conceded just 5 goals. I can't remember where Liverpool ranked on goals conceded from set-pieces, but it's not the highest, and not even the highest out of the top 6 or whatever.