The issue with Evans is that he's quite similar in playing style to how Rodgers has been this season. Easy on the eye but as soft as a chocolate fireguard at the back.
That said, he does bring experience with him and a link to the old ideals, which isn't too dissimilar to what Rodgers is trying to bring back. He isn't totally outspoken nor egotistical and works well as a number two, so wouldn't come in as quite the figure of authority and worship that Kenny did, so in that sense perhaps it could work. I guess the crux of it is that anyone like this coming in would be too similar to the Director of Football role that caused so much uproar, ie the club appointing ANY staff would go against what Rodgers is trying to do.
As said though, Rodgers himself either needs to get his defensive side together this Summer, or bring someone in who can assist him.