Donnie acquired Breton Bank, but from this deal alone, it actually wasn't a particularly astonishing transaction.
However, from a strategic point of view, it could be said to have filled the last piece of the puzzle in Donnie's business territory.
With this piece in place, Donnie's New Jersey Consortium could be considered officially established.
If the United States were seen as a cake, then Donnie's New Jersey Consortium was now ready to formally join the table and share a piece of the cake.
The key issue was that the cake hadn't grown any larger with Donnie's entry; it remained the same size, meaning Donnie would need to take portions previously held by others.
If Donnie had tried to do this before the founding of the Tarot Society, Mellon would certainly have disapproved, since he, too, was one of the beneficiaries of the cake's distribution.