Well I guess that's where I differ. Wan B is a better RB than both of them
He's a more "proven" option than both of them, but mostly not in a good sense. By playing Malacia there, it could be useful as part of his development as he gets some experience even if he's not playing his best position so that's an opportunity cost of playing a failed player in AWB there.
I don't like it, I don't like playing centre halves and players on the wrong side at full back but I dislike AWB and what he offers just as much. You say he's going to press and has pace but that's based on athleticism, upstairs he lacks urgency, lackadaisical on the pitch and has never actually improved, so in my opinion those characteristics run counter to him doing so. Sometimes he doesn't even get back in position.