He wasnt really in thar position pre Klopp for long was he?
He wasn't the actual sporting director till 2016. Before that he was technical side so would have had input along with Hunter and others. But I'd put money on him being part of the group that pushed for Coutinho,Sakho,Can Markovic,Origi, Firmino,Gruijic,Gomez etc. I doubt many of those was Rodgers
After that convincing Klopp on Mane and Salah over Brandt and Gotze.
Others who didn't work out, but obviously decent players as shown elsewhere Luis Alberto and Aspas
I wouldn't dismiss his input at all, but it would be interesting to see how it worked out without one of the best of his generation as manager