Koscielny was never a world class CB. Arséne Wenger isn't a terrible manager, he just puts faith in sub par players. All our midfielders and defenders are average at best, Ramsey is the only one that could do a job but even then he leaves the defenders and the CM next to him stranded. If we had better players Arséne wouldn't look so bad, which is obvious (which also goes back to squad cost lol). Özil as our marquee player was never gonna run the team like Fabregas did, he's one of the reasons for our form. Can't make something happen on his own like Cesc, RVP or Santi before him.