What do you think has happened to Crocodile since Marineford? We only know that he went to the NW with Mr 1 and that we have seen him in an office (probably his NW base of operations) reading the newspaper.
My theory is that he has recruited a new crew similar to his original crew (not Baroque Works), with people he trusts as Mr 1. I also think that after Doffy's fall he has tried to become the new Joker of the Underworld, since he is equal or more intelligent than Doflamingo. Finally I’m sure that when he appears again he will be much stronger than in Marineford, possibly with CoO and CoA.
My theory is that he has recruited a new crew similar to his original crew (not Baroque Works), with people he trusts as Mr 1. I also think that after Doffy's fall he has tried to become the new Joker of the Underworld, since he is equal or more intelligent than Doflamingo. Finally I’m sure that when he appears again he will be much stronger than in Marineford, possibly with CoO and CoA.