Otamendi will be fine under Pep. He very well could be World Classish under Pep. Fernando will be fine too. The others I can't vouch for.MP and Pep's styles are like chalk and cheese, players that will struggle under Pep:
Zabba
Kolarov
Otamendi
Demichelis
Yaya
Nasri
Silva
Fernando
Bony
Just my opinion but can you see a common theme with all the players above?