Agree on that. Yes, Calabria holds the title of head of FHFA. But we all know how this administration operates. It is top down.
Whatever Trump wants is what Trump gets from his administration. He is not one to have subordinates convince him otherwise. That being said, I dont believe that the GSE's are currently high on his list of things to help him get re-elected.
So I see him trusting Mnuchin as his right arm in this situation, as he and Trump appear to always be in lock step. Therefore the true power in this matter is coming from the Treasury Secretary, as the President's surrogate. And I see Mnuchin as viewing Calabria as an academic pawn to be used as he pleases.