Basically a new director of football came in during the summer, upset a lot of players, let top players go, brought in complete unknowns to replace them and then hired a manager who had never really achieved anything of note and had never managed at a particularly high level and was known for playing defensive football, which is something Ajax has never played. A complete recipe for disaster and it proved to be. After fans rioting, the club finally sacked the director of football as they realised that he was the instigator of the problems and they gave the manager a little more time. The players were happier and the players who had left the club celebrated the sacking on social media. Ultimately the manager, Maurcie Steijn could not turn things around and appeared tactically inept, so he was replaced by club hero John van 't Schip and things have been on the up ever since.
I would expect Villa to win both legs but the league table doesn't tell the whole story of Ajax's season so far.