Walker was such an asset because of his pace and athleticism. A bit careless at the back, but he made up for it with his attacking. He was often responsible for lethal counterattacks. Scored a handful of great long-range goals too. And we should never forget his incredible Halloween pranks. Multi-talented.
Trippier was more solid at the back, but still not great. Lacked the pace to help significantly in counterattacks but was generally a decent crosser. His biggest problem was inconsistency. When he was off his game he was really off.
I actually like Aurier. For me he’s a better defender than either Walker or Trippier. He’s good at winning the ball back, and is much better technically. At times he reminds me of a right-sided BAE. In attack he gets forward better than Trippier, and whilst his crossing is more inconsistent than either Walker or Trippier, it feels like he puts more crosses in, with at least a couple a game that create decent chances.
The obvious flaw in his game is his ability to silence that little voice in his head that says ‘don’t randomly fly in to someone from behind’. He plays with passion, and unfortunately that leads to red cards and penalties. If his decision making was better he’d be a great full-back.
He gets a lot of criticism because of the red mist moments (including from me), but he’s also put in some brilliant performances. And he has that beard.