I think Liverpool have a solid squad and they are still worthy title contenders. They have a new manager because Klopp wants to take a break from football. Arne Slot will have no problem with the team he has now. But as you said Slot has to be careful and has to be able to rotate the squad well to minimize the risk of injuries. It will be a problem in his first season if many players get injured. But I think it is difficult to avoid injuries because no one knows their unlucky day.
Because no one knows when each player can get injured, that is what will make the coach think about being able to rotate players very well before the players get injured. I also see Liverpool's squad which is still quite solid at this time so that the Liverpool team will still be considered by its rivals in the Premier League because there are still some of its mainstay players who have not moved to other teams so that Liverpool must still be considered a strong team in the Premier League this season.
The league hasn't started yet and we can only see what Liverpool have achieved at the moment which is only the result of a friendly match where the team didn't play all out in a match, but looking at what Liverpool has shown so far in several friendly matches there is certainly hope for fans to see their team will be better next season, currently Liverpool has not recruited any new players in the transfer market but if Arne slot can optimize the current squad in next season maybe we can say he is a great coach, but with limited squad it seems it will be difficult for a coach to be able to maintain consistency and also the performance of the squad when they have to face a busy schedule.
Last season Klopp was able to bring Liverpool to end the season in 3rd place and of course that was a good achievement after their squad had player injury problems, even though at that time Klopp squad was also very limited but he was able to rotate players well to compete in the English league, europe and the FA, because Klopp skill in seeing the potential and also the ability of a player to play in another position that is not his position has been very effective so far in filling the holes left by injured players, so if Liverpool don't bring in new players at this time of course Arne slot must be able to do what Klopp did last season.