Robertson, Alexander-Arnold, Milner, Henderson, Matip, Wijnaaldum, Salah, Firmino.
Some of this guys weren't even rated before Klopp. Milner was a meme for what Messi did to him. Firmino and Salah were two good players and that's all, nowhere near the players they are now. They came from Roma, and Hoffenheim ffs.
Salah was a Chelsea reject who did well at Fiorentina and Roma. Everybody here made fun of Salah in Roma vs Madrid for being a pace merchant and not much else.
Only world class player, or even close to that, that they ever signed under Klopp is Van Dijk. Every other player has grown leaps and bounds under Klopp, and this is why they are where they are.
Same as Borussia Dortmund really. Dortmund were just a good team in Bundesliga, but nothing spectacular, before Klopp. He came, made them back to back Champions and CL finalists, all while playing some of the most spectacular high-octane football in Europe.