That's difficult to tell. Quite often players who are supposedly great fits to a system struggle while others surprise. I think in the beginning his character will lead to a very positive attitude and could improve the mentality of the team a lot. They have a decent mix of individual quality and workhorses, so that's something to work with for Klopp. Benteke, Coutinho, Firminho are good talents in attack. The midfied's a bit dire but not that bad.
I don't rate any of their defenders and Klopp struggled to adapt his defensive set-up once the Bundesliga teams figured out how to play against his pressing, that's in my opinion the biggest question mark. We'll see if he learned something from it and how the Premier League clubs react to his tactics.
I don't think anyone should expect him to come midway in the season and turn them into a top 4 team within a few weeks. If they miraculously pull off a top 4 finish, it'll be because they went on a crazy run boosted by a change in mentality along with one of the top 4 teams fecking up big time (Chelsea continues to struggle, United or Arsenal collapse, something like that). 5th or 6th with a positive development in playing style this season and then a challenge for top 4 the following season is a likely outcome in my opinion.