One thing I've learned watching the Ligue is that you have to try and be balanced, a player who is decent/good in the Ligue isn't necessarily good enough for a higher level league. Only the top players in Ligue go on and succeed in higher level leagues. For example, Lichtsteiner back when he was at Lille, was the best right back in the league, you'd expect him to go on and do well, the same could be said of Sagna and Maicon. Then you have someone like Remy Cabella, he was always talented, he was decent for Montpellier but he was never one of the best players in the league, I won't be surprised if he doesn't make it in the EPL.
Ocampos has been quite good for Monaco, thats why L'OM brought him in(plus he's Argentine, thats an added advantage for Bielsa), is he one of the best players in the league? No, not even close.