That makes no sense whatsoever. ALPA's merger policy is negotiate->mediate->arbitrate. No promises since going to arbitration is always a crapshoot. What possible other methodology could ensure one side doesn't take advantage of the other?
Pilots have proven over and over that given the chance they'll craft an integrated seniority list that "protects" their own and screws the others. Witness AA/TWA and what USAPA is trying to do. You don't want to be compared to either of those scoundrels, do you?
Has there ever been a merger where it didn't go to arbitration? If not than why the first two steps? I think most arbitrators will go the non DOH route so why aren't we smart enough to just do it ourselves? Oh ya that silly little thing called a DFR lawsuit that makes the union "protect their own".