There is no third method.
The newly elected representative entity now represents the same groups that entered into the arbitration.
They have what is called a Duty of Fair representation to those same groups. To forward the well documented proposal of one group to its great enrichment at the direct discriminatory expense of the second group would be considered by any jury as a failure of its DFR.
The former representative is gone, not those represented.
In essence, whether I am represented by ALPA or usapa, I still have a contract with you and the company that says we use the Nic. Either tries to weasel out, I sue.