I hear what you are saying, but any contract that is not consistant with the law in that State, or violates any US Federal LAW would be null and void. We can make contracts, but they do not supercede US LAW!
The dispute arises on the claim that one of the parties was unfairly removed as trustee(s).
You are assuming there is a state or federal law that would apply in this instance to determine any unfairness. I don’t think so; but if so, it is likely that would have been brought to the judge’s attention.
My sense from the poorly written article is that they have not yet had a hearing before the arbitrator. If that is true and the award is contrary to some state or federal law, then the disappointed party can be expected to appeal with a “void as against public policy” type of argument as one of their complaints.