Despite owning Klopp's squad legacy, but Slot knew better about United rather than ten hag. If you're watching Slot's post interview, then you would see how he was breaking down Ten Hag's pressing. he even exposed United's tactic to the public.
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.
What Slot said should be a lesson for Ten Hag to improve the game strategy he is currently implementing at Manchester United, I think Slot is quite familiar with the strategy implemented by Ten Hag because the two of them were once rivals when coaching the Dutch team and Ten Hag continues to apply the same style of play that he has been using at Ajax , so that it looks very monotonous without any strategic reserves to anticipate the game strategy of his opponents and this was clearly visible during the match against Liverpool yesterday, slot and ten hag have often met Previously in the Dutch league, Ten Hag should have tried a different tactical approach and strategy when he had to play against Slot, because with that I thought Ten Hag would be able to surprise Slot with a different game during this time but in fact he is quite proud of his current game strategy.