Steve Cohen entered his new Mets’ gig with high expectations for the staff that would surround him. He brought in Sandy Alderson as team president quickly and smoothly. The Cohen-Alderson group advertised its desire for a modern front-office structure, one the Mets have sorely needed for years now.The new owner was met with push back on filling his president of baseball operations position — he didn’t expect the kind of resistance that eventually led the Mets to pivot and alter their plan.“I’m a little surprised we haven’t been able to find people for the front office,” Cohen said during an in…