I think Cordero, solely due to his injury history, needed to start in AAA just for the reps. Unfortunately, the AAA season didn't start until May this year. Franchy probably has a higher ceiling than Dalbec.
Should Dalbec deserve more leeway? No. He's played well the past week or so, but he has a streaky profile just because of the swing and miss in his game. If they thought Chavis would be an upgrade over Dalbec, Dalbec would be in AAA. I think we're stuck with Dalbec at 1b until Casas is ready because none of the other 1b guys can hit right now (Santana, Chavis, Marwin).