Having spent a fair amount of time in and around the Qantas IR department I can assure you the individual unions are pretty powerless. They have an entire floor of strategists who have planned how too play one off against the other and what timeframes they are willing to settle each group to maximise the pressure on the rest. Qantas already knows by whom and how these aircraft will be operated and what time they will be introduced. The negotiations are just window dressing.