Strangely enough, I do agree that Koscielny has always been overrated by Arsenal fans. He’s definitely above decent and has been one of the best CBs in the last half decade of the PL. I just always felt he lacked the concentration of an elite CB and that’s always what held him back from being world class to me.
When he first arrived I saw shades of some great defenders in his ability to read the game and snuff out danger but I don’t think he’s improved on the mental aspect of the game enough.
One of the best CBs in the PL, and for me he certainly deserves a spot in any discussion of best defenders to play unseen Wenger. He just falls short of world class for me.