When you see an experienced manager who knows how to study the tactical structure of his opponents before playing against so he can device a means of coming top at the end of the day, you'll definitely not struggle to notice about his professionalism. Arne Slot came to Liverpool and started with by studying the tactical approaches of his predecessor Jurgen Klopp which was why he was able to use the squad at his disposal effectively without even adding a new player in their mix. Like you rightly said, he exposed the weakness of Erik ten Hag's tactics which was why deviced the best tactical approach to get all three points from the game at Old Trafford yesterday and that actually worked perfectly for him.